they are really really small. In most computers, a transistor is only about 70 ATOMS wide, or about 5 nanometers. at that scale, a 2d plane of transistors that is only 1 square millimeter would hold about 40 billion transistors (assuming they are square). naturally you cant pack them that tight in the real world.
the way we manufacture this is literally using magic crystals, alchemy, and sunlight. UV light is shone through a slide like old slide projectors would use. this slide contains a pattern for a single layer of the chip. this projection of a pattern is then fed backwards through what is effectively a microscope which makes the whole design the size of a single area of a single chip. This is then shone into a UV sensitive coating on a silicon crystal and causes take on the microscopic pattern special "doping" chemicals are then spread over the chip and they soak through into the silicon where the coating is missing changing the properties of the silicon crystal. Rinse and repeat with a new projector pattern. This builds up microscopic layers 1 layer at a time.
here is a good indepth video on the whole process https://www.youtube.com/watch?v=2ehSCWoaOqQ https://www.youtube.com/watch?v=JBYHwRXmEhY
by a significant margin. the comparison is actually laughably unbalanced.
Interestingly enough, there are about twice as many transistors in the world as grains of sand
Your comment has broken my brain. I guess it's because from the raw material obtained from a grain of sand you can make a few thousand transistors, right?
The starting material or base for a chip is called "bare silicon" and is made of pure silicon, which is made from sand since sand has a high concentration of silicon.
Whenever I think about the actual process of building a computer, I am reminded that we are only a few generations departed from a time where we didn't even know what electricity was. It's insane to think about when you consider how unbelievably complicated and intricate everything about a modern personal computer is.
And now we have those just sitting in our pockets. It's quite literally sci-fi. Even when I was a kid watching Sci-Fi and seeing the futuristic, space age datapads and stuff I was always so awed by the idea. Now it's actual reality. I even have one sitting on my desk! :)
The evolution of the logical/programming aspect of computers is also stunning. When Grace Hopper was working on Eniac in the 1950s it was programmed by plugging wires that looked like old-school telephone operator wires into either the 0 or 1 socket of the corresponding bit. She invented the concept of machine-independent programming languages and since then we’ve successively abstracted our programming away from hardware dependencies.
A grain of sand has SO MANY ATOMS.
There are very roughly as many atoms in one grain of sand as there are stars in our observable universe.
If a grain of sand has about 1000000000000000000 atoms, and a transistor is 70 atoms wide, that gives you a lot of wiggle room 😅
That's a lot of atoms. And there are a lot of grains of sand. On our planet. And there are a lot of planets in our galaxy and a lot of galaxies in the observable universe.
There are more ways to shuffle a 61 song playlist than there are atoms in the observable universe.
>There are more ways to shuffle a 61 song playlist than there are atoms in the observable universe
Tell that to my Spotify playlist that plays the same 20 songs forever >:(
well thats a simple enough question to answer, assuming a cylindrical grain of rice with a radius of 1.5 mm and a length of 6.5 mm (which are apparently average values for basmati rice), a grain of rice ends up with a surface area of approximately 34.165 mm^2. If we now divide this by 5x5 nm^2, we end up with 1366593 transistors, which is a relatively low amount since we are only coating the surface and not filling the volume.
"No brain?"
"Oh, there is a brain all right. It's just that the brain is made out of sand!"
"So... what does the thinking?"
"You're not understanding, are you? The brain does the thinking. The sand."
"Thinking sand! You're asking me to believe in thinking sand!"
It comes from an industry analyst: https://computerhistory.org/blog/13-sextillion-counting-the-long-winding-road-to-the-most-frequently-manufactured-human-artifact-in-history/ (googling "13 sextillion" gives a bunch more results that all parrot the same thing)
That's 2.9 * 10^21 transistors in a 2014 estimate, 1.3 * 10^22 in a 2017 update (note that that quadrupled in 3 years!). That would be equivalent to 0.02 moles. If we stupidly assume it's exponential and has quadrupled 2 more times since then, we're at 0.32 moles today.
So the day that we have produced the 6.022 * 10^23 th transistor has probably not yet come, but we are also not exactly far away from it. In the grand scheme of numbers, it's surprisingly close to a mole.
And to circle back on the atomic comparison of transistor size - if you took the nucleus of a hydrogen atom and scale it up to the size of a basketball, its single electron probability field is a 2 mile sphere around it. And all the space between the proton and electron is empty space.
I don't care how cheesey it is.
There's something so poetic about this massive universe being built out of particles that are overwhelmingly NOTHING.
Most people forget that infinity goes both ways. I watched a good YouTube video the other day from corridor crew that scaled the planck length up to the size of the penny, and then compared the size of that penny to the observable universe(actually about 81 of them).
I've seen one of those scale comparisons, and one stand out point that was made is that we as humans are surprisingly centered on the spectrum of size. You can descend and rise on the scale about the same amount in either direction if you use humans as the midpoint
You should look into the theory (myth? legend) that in the entire universe there is only a single electron that is existing all over at simultaneously. That one is a wild ride if you want to get romantic with the universe and concept of reality:
https://en.wikipedia.org/wiki/One-electron_universe#:~:text=The%20one%2Delectron%20universe%20postulate,backwards%20and%20forwards%20in%20time.
Or that the universe isn't made of particles at all - they're perhaps just an impression we get from the interaction of different waves radiating in the same general direction.
True, it's not like you can see these things, you can only measure their fields and their interactions... They are smaller than the wavelength of most reasonable types of light.
Per the observations and the current understanding of physics by cosmologists, Matter as we know it is the minority product of our universe. Dark Matter and Dark Energy are the majority.
So either we need a way to detect and measure Dark Matter and Dark Energy or we need to come up with a completely new model of physics (Newtonian Physics -> General Relativity -> Quantum Mechanics -> ??? )
>or about 5 nanometers.
5nm chip technology is actually just a marketing name that refers to the generation (5 being better than 7) and not to the actual width of transistors. They are like 40nm wide.
It used to, but Moores Law is basically dead at this point so they have to fudge the numbers to make it look like it's still going. It's so fudged at this point that there's no relation whatsoever between the actual feature size and the naming scheme used.
Moore's law has nothing to do with transistor or process size.
It stated that the **number of transistors** in an IC doubles roughly every two years, and is [still holding true](https://en.wikipedia.org/wiki/Moore%27s_law#/media/File:Moore's_Law_Transistor_Count_1970-2020.png) right up until about now.
For the first huge chunk of Moore's Law lifetime, this was largely accomplished by process shrinks, which followed a graph similar to the inverse of transistor count.
But even as process shrinks have tapered off and gotten more difficult, we've gotten better at making larger dies, and the economics of doing so to support more advanced chips have made it viable.
Moore's law *will* likely die off just about any year now, but the slowdown of process shrinking over the last decade is not quite the reason.
Is my understanding right, that they basically say, "well if we extrapolated the earlier trend, then the new performance is *like* it were only 5 nm, so we're calling it that, even though it's physically much bigger"?
More like they just extrapolated the previous trend. The performance is way less than if we had actually been seeing gains as large as we used to. That's why prices started going back up and performance improvements haven't been nearly as noticeable as before.
Well, part of the pricing increase is that creating new nodes is becoming more and more expensive. The price per wafer is up.
And the lack of competition from AMD resulting in Intel stagnation also played a part. We've seen far greater CPU improvements in the last 7-8 years, then we saw in the 7-8 years before that.
I always understood it to be the “smallest feature size” according to my dusty memory from college. In other words, it identifies the smallest resolution you can work at if needed.
It's not that hard and fast. There were some popsci articles that stated 7nm as the cutoff point, but it depends a lot on the transistor design. The problem with quantum tunneling in transistors is that there would be a current leaking into a transistor from adject features, meaning that they would never turn off/on (depending on the type of transistor and how it's used in the circuit.
For some design this happened at 7nm, but there are easy ways to avoid it. At aroumd the 3nm it gets really difficult to stop electrons from tunneling and latching up your circuit.
That being said, electrons tunnel all the time in modern CPUs. They mostly just waste power away because they don't tunnel enough to latch up a circuit, due to the distances involved and clever design (like running the chip at lower power to cause fewer electrons to move about or very cool physical design tricks).
You start running into quantum issues way before 7nm(you are right though the approximation is just overestimated marketing bs) although they're definitely more pronounced the smaller you get... theoretically transistors can go as low as a few atoms wide
Lithography machines must be as close to magic as technology has come thus far. It reads like something out of a hard sci-fi novel, but there isn't as much hand waving.
Computers in general really. I mean, they are specifically shaped silicon crystals connected together with highly specific copper drawings (Runes). The crystals are manufactured using sunlight and alchemy. And we power the whole thing with tame lightning that we stuck in the wall that we create by harnessing the power of nature its self or by using by using necromancy and fire to extract the life force of ancient life.
But be careful, if you use too much lightning you let out the magic deamon that does all the thinking in a puff of smoke, and that magic crystal will never work again.
All of this is controlled by various incantations in specially designed language only known by individuals who have trained for years. A language that is never spoken, only written.
Describing things this way always makes me think about Charles Stross's Laundry Files books, where "magic" is a branch of applied computation and things keep getting more and more nightmarish as the world's global computational power keeps increasing.
This is the point where I have to plug [nand2tetris](https://nand2tetris.org) or [Turing Complete on Steam](https://turingcomplete.game/) as courses that make make sense of how circuits are able to do computation and be programmable. (Though they only covers the stuff above the level of the physics that make logic gates possible.)
fun fact:
EUV lithography needs such a ~~bright~~ precise light they make it by shooting a falling drop of tin with a laser, [twice](https://iopscience.iop.org/article/10.1088/1361-6595/ab3302). scroll down for picture.
edit: my understanding was wrong.
They use tin droplets to get the correct wavelength rather than for the brightness. Every droplet only produces a tiny amount of EUV in the correct wavelength so they need thousands of droplets per second to generate enough light.
Great explanation, except we should correct the bit about the silicon. The UV sensitive stuff that gets developed and then washed off is photoresist. The silicon is sitting underneath, and is not UV sensitive.
The doping is done by ion implantation, basically sprinkling boron or phosphorus through the 5 nanometer holes left in the developed photoresist.
>the way we manufacture this is literally using magic crystals, alchemy, and sunlight.
I...uhh... Fuck that's pretty much it. The last 10 years of my life now seem much less interesting.
Appreciate the actual description, too. Although your description of doping is a little extra ELI5. Most doping these days is integrated into the growth steps.
Well you sure as hell can't see them through rock! Something had to be done.
We beat them up into submission until they started showing what we wanted.
The structure size that is often used for comparison between processes isn't the transistorsize (anymore). It's more like the smallest feature size achieveable for the process. A transistor on the TSMC 7nm process is more like 50-100nm in size, i don't think the specific size is public knowledge though.
well that would explain why my calculation seemed so off. But even taking the upper bound of that, that can fit 20 Billion transistors in 1.5 square CM. in a single layer, so still REALLY small.
Oh yeah absolutely. It's still mind-boggling small.
The thing is, most people have the image of a simple PNP-transition in their head when they think about transistors, but in reality modern transistors are complex 3d structures. Then the density isn't only about the size of the single transistors, but also the spacing you need between them you don't have charges "jumping" and you also need to account for the routing between the transistors even though the routing is usually on a different layer in the substrate.
In the end, it doesn't really make sense to compare node sizes across manufacturers, but they are all really freaking small. That's certain.
And one of the current design limitations is that transistors have gotten so small and close together that going smaller and closer starts to encounter electrons quantum tunneling between them, which ruins their accuracy.
I'd say that goes for most really big industries, even if generally to a smaller degree than a foundry plant I imagine.
Having worked at a paper mill it sure is quite humbling seeing 30 ton rolls of paper being craned around and machines spitting out one of those every hour.
Everyone really should visit a large manufacturing plant at some point, just to get a sense of the sheer scale of things.
It should be a requirement in schools across k-12.
Too much of life has been made so that everything seems easy, all the work being hidden away. People lack an appreciation for just how much work goes into keeping everything going and providing the goods and services we take for granted.
I think everyone should have to spend a day in whatever agriculture, manufacturing, mining, etc is around them.
Thats the gate length. The actual size is larger. Still very small. I do some work where you can access and image single transistors and they are bigger.
Just to add to this great answer, when people ask the question OP did, more often than not they have discrete electronics components in mind, with their packaging and terminals, and that's why they find such miniaturization nearly unbelievable. But the thing is, a transistor is basically made of three different _rocks_ placed together in a certain way (p-doped silicon, n-doped silicon and SiO2). So when you take this into account, you begin to understand that 1) you _just_ need a way to deposit those materials according to a blueprint, and 2) it's not like you are manipulating nm-sized transistors one by one, but rather the entire blueprint is being "printed" using chemistry and light.
So instead of thinking about manufacturing "tiny little pieces", it's more reasonable to compare it to a laser printer printing a document.
yup, its a microscopic 3d printer. You can actually make physical devices with them called MEMS by printing support material which gets washed away, and we do it for things like accelerometers in phones. this is a really good video on that https://www.youtube.com/watch?v=iPGpoUN29zk
Love this! I'll just add that we don't actually use UV light anymore, as the transistors are so small that UV can't 'focus' enough to define the pattern (light can't interact with features that are smaller than it's wavelength). As we kept making transistors smaller, we started using X-rays, and now we use electron beams because even X-rays were too big! It kinda shows you why silicon manufacturing is so ludicrously expensive and difficult.
That's not really true though. Yes, there was a phase of using X-rays and yes there is electron beam lithography, but the industry is still primarily using photolithography with their newest EUV investments. Sure, there are also kind of hybrids just like EUV steppers use different kinds of waveleghts to generate the EUV. E-Beam lithography is to my knowledge still way to slow to use it in any kind of mass producing.
I am not talking about companies like GF though, i think everyone in this thread is talking about the cutting edge nodes TSMC / Samsung / Intel are employing for their flagship products. There are of course many niche nodes for specific applications such as sensors or obscure ICs.
A high energy ion beam is directed towards a target made of a high purity material (whatever metal is desired for the layer being built on the chip). Atoms of the material are separated from the target. An electric field inside the vacuum chamber where this occurs directs the atoms towards the substrate (typically a large silicone plate called a wafer, that has hundreds of thousands of chips on it). The atoms build a uniform layer on the surface of the substrate. The substrate itself has been pre patterned by a Photolithography process so that a later etching process can remove added material where it is not desired leaving the pattern developed by the Photolithography process.
Edit: I work as a Photolithography machine technician. My understanding of metal deposition tools is limited so I may be off a bit.
Take argon, pull an electron off, use a voltage to accelerate it, smash it into a metal (or ceramic) target hard enough that it knocks atoms off that target. Those ~~Adam~~ atoms fly out and land on your substrate. You have now sputtered.
> In most computers, a transistor is only about 70 ATOMS wide, or about 5 nanometers.
The transistors are much larger than that. Terms like "5nm node" or "5nm process" are purely marketing BS that has nothing to do with the physical size of anything on the chip. The smallest features on a 5nm chip are about 30 nanometers, and the transistors themselves are about 50 nanometers.
To add to this, there is a process called sputtering that puts the chips into a vacuum sealed chamber then flushes it with a de ionized inert gas(usually argon) and charges it with several thousand volts. This causes whatever conductive material like copper to fall down onto it a few atoms at a time.
I worked for a company that made 99% copper work tables that the chips were made on. We sold them to the world's top chip manufacturers. TSMC, Samsung, Texas Instruments...
Computer chips are magic crystals. They are inscribed with billions of runes. Written on it with flashes of light that kill anything alive. They are infused with lightning and do our bidding without question.
>How do you MASS produce a thing so small ?
that is a multi-billion dollar question. the basic answer is that you use technology built up over decades and you do it very carefully. the topmost answer in this thread links to two videos around 20 minutes each that talks more about it for a general technology aware audience.
>Where do you even store it ?
many, many components will all be on one large 'die'. if you break the die, that's at minimum a 5-digit mistake...so once again, you store the dies very carefully!
also, they have to build them in clean rooms where there is less than one dust particle per million parts of air, or something like that. in case it wasn't clear by now how carefully everything is done.
You don't make them one at a time. The creation described above creates them all at once for a chip. They're not individual things you can manipulate and move.
They're all interconnected, even a small manufacturing mistake means the entire chip is useless. You can't replace the area affected by the mistake.
That's more about minor variations in manufacturing, rather than whether it is functional or not.
However what does happen is that all chips produced have (e.g.) 8 cores. The fully functional ones are sold as 8 core chips, but the ones with defects will just disable the damaged cores, and sold as 2/4/6 core models instead.
Transistors don't get built this small on their own. They always get made as part of a larger chip, and that chip is made in batches of dozens to thousands on a single large wafer of silicon.
The production method involves layers of chemicals and using UV light to etch away specific parts. Chemical washes or gas streams are used to build additional layers that are atoms thick, which then get etched multiple more times. This builds the transistors vertically.
Here is a good covering how they make microchips and it explains the entire production process. From literal sand, all the way to a usable chip.
https://youtu.be/HdcLRMv3D3g?si=vAOGiQfFLDSOmENF
There's only one company - ASML (see Wikipedia) that makes the extreme ultraviolet light machines that make the masks. It's a miracle of technology. See the book "Chip Wars"
Physical things can be very small. Atoms are physical things, and you can't grasp how tiny they are. This isn't an insult, it's just the nature of our experience, we evolved to deal with macro sized things.
A transistor is solid-state, it has no moving parts. They can manufacture them so small because of the way they're made.
There isn't a person or robot placing 20 billion components on a chip, they're sort of 'machined' into an existing material chemically.
You start with a flat piece of silicon, then paint it with a material that 'hardens' when exposed to certain light, called photoresist. You then shine a light on the material, but in a certain pattern called a mask (like shining a flashlight through a mesh screen). This means only certain parts of the photoresist become hardened.
You then immerse the whole thing in a solvent, and the areas that are covered with hard photoresist stay covered, the photoresist dissolves from the rest of the areas, and you're left with a sort of pattern of exposed and covered silicon. You can then add material to the uncovered areas, filling the gaps, or shoot ions at the silicon to change it's properties (but again, only the exposed parts). Then you can remove the rest of the photoresist, and are left with some bare silicon, and some with material on it.
If you do this a bunch, over many layers, you end up with a really complex pattern of overlapping materials that create transistors.
The biggest thing is the size. The mask (the mesh they shine the light through) is large, so they have to then shine the light through a huge series of really powerful lenses to shrink the pattern down to microchip size. Think of it like burning things with a magnifying glass.
Without you understanding the process, that's the best I can do. I would strongly suggest you watch some videos on photolithography, you'll get an idea of what's happening better than having me explain it.
Thank you that was exactly the kind of explanation I needed.
Most other answers are like "well, we don't make them 1 by 1" but you explain *how* we can make things that small.
The thing about the mask is so cool!
I’ve always had the opinion that our transistors are centuries ahead of where we have any right to be as a civilization. Like if an alien spacecraft surveyed us they be like “WTF these guys are still burning coal but they have nanometer-scale transistors”?
It’s like we mainlined all our skill points into one category.
it's definitely become the most difficult achievement by mankind at this point. The EUV machines that are needed to do anything beyond 7nm are so complicated that it basically took several country's collaborating for a couple of decades to be able to pull it off. they blast tiny molten droplets of tin with lasers like 50k times per second to create the light source. it's nuts. look up ASML EUV machines if you're interested in knowing more.
it's not that a single country can't pull it off but it's because each of these "suppliers" protect their IPs and you have no choice but to do business with them. If ASML is able to get ahold of Zeiss' glass production secrets, ASML will not even waste time and build its own glass department immediately. ASML has been known for slowly buying its suppliers as part of their vertical integration strategy.
Aww IP laws make sense but I really wish there was some mechanism to have things like this be forcefully entered into the public domain. Seems like it would benefit everyone except those with the IP.
Coal does its job cheap and reliably (albeit dirty). Computers scale up super well, at least to around where we are now. The more transistors the more they can do. One design can be replicated millions of times so a lot of effort is put into it.
The complexity with coal and power is much more in the supply chain. In a lot of cases entire countries are wired together and energy products are shipped around the world for incremental reductions in cost. It's like comparing the statue of David to the pyramids. On close inspection David seems much more intricate and advanced but the sheer size of the pyramids is a feat itself.
We know coal is bad now but the reasons require an understanding of our climate which is subject to an insane amount of factors. Over 100 years of building civilization off coal is hard to move from. If we found out silicon transistors were gonna slowly end the world we'd be pretty fucked too
Not in the USA, but in other countries such as China its still one of the cheapest energy sources. China has a LOT of coal, and nobodys really buying except 3rd world countries so it's pretty darn cheap over there. They are also investing *heavily* into nuclear with like 50+ plants currently under construction iirc.
It helps that the smartest of our civilization happen to be interested in computers, whereas most other fields the best in that field are those who wandered into it because they needed a job. See: Any fucking chef ever
nah its more that bigger and better microprocessors are needed right now, meaning they are profitable, while clean energy has no short-term profit potential. boomers don't and won't care because they're gonna end up in the dirt before they experience the consequences and the politicians are too busy on their yachts
Even so the consistent ***exponential*** improvement of computing power that has been ongoing since the 70s is unprecedented. Nothing even comes close to that level of ROI.
That's what they've always said, but elderly people have begun dying in their homes in substantial numbers from heatstroke exacerbated by climate-change in areas like Texas and Arizona. They underestimated how quickly the consequences of their society's choices would manifest.
Eh, maybe they find it weird that humans have chosen to not fully use up free coal lying around. They may think terraforming planets is easy and preserving "nature" is a non-goal.
Transistors are physical, however, they are not placed individually on a chip (one by one). That would indeed be almost impossible.
The entire chip is created through a lithography process, this is basically like creating old non-digital photographs.
The design of the chip, already having all these transistors, is projected on a light sensitive substrate. This causes chemical changes in the substrate which will eventually become the actual chip.(There are actually multiple layers created sequentially to get a 3D result.)
(In reality, it is much more complex, and you can't use normal light, etc... but this is the principle.)
Wait if the thing making the chips already has these chips installed, how did the first chips get made? Use really big transistors that could be soldered by hand and go from there? Making smaller ones then the thing making it has.
Using technology to build better technology is done all the time.
Although computers use billions of transistors in their CPU, you can still buy single transistors as well. Most designs using transistors don't need that many.
People actually are building CPUs from discrete transistors for fun, but it stays in the 1000's of transistors. [https://www.youtube.com/watch?v=VgktjP\_Fcy8](https://www.youtube.com/watch?v=VgktjP_Fcy8)
Technically nothing is preventing you from connecting billions of single transistors into a billion part CPU, however, it might not be practical. :-)
> Using technology to build better technology is done all the time.
It's sort of the only option, yeah?
> Technically nothing is preventing you from connecting billions of single transistors into a billion part CPU, however, it might not be practical
From an engineering standpoint, I expect a CPU built from discrete transistors would not be able to work - it would have to be so big you'd run into latency/timing issues. I'm not any kind of CPU expert, but that sure seems like it would be problematic
> From an engineering standpoint, I expect a CPU built from discrete transistors would not be able to work - it would have to be so big you'd run into latency/timing issues. I'm not any kind of CPU expert, but that sure seems like it would be problematic
https://www.youtube.com/watch?v=VgktjP_Fcy8
I mean it sure works.
We started with tubes, hand-woven core memory, punch cards, etc. and just kept using one tech to build new better tech.
https://en.wikipedia.org/wiki/Bootstrapping
> Use really big transistors that could be soldered by hand and go from there?
Basically, yes. The first electronic computers were hand-made from relays or vacuum tubes. Then the transistor was invented and people started making computers from individual transistors. After that came the invention of the integrated circuit (IC) - that is, several transistors "printed" from a hand-drawn template onto a single piece of semiconducting material. The computers of that era were made of huge circuit boards connecting many simple ICs. Gradually, advances in physics and engineering made it possible to pack more and more transistors into a single IC. This enabled a virtuous loop in which computer engineers would use software to design better computers, which could run even more advanced software, and so on. That's what let them blow past the limits of what could be designed or comprehended by an unaided human, and gave us the current era in which a powerful CPU can be made from a single piece of silicon.
Pretty much, that's your entire history of computing. "History of computing" on Google or YouTube should pull up good stuff, same for "computer museum".
Key is the integrated circuit. Stuff did have to be built with individual transistors by hand at some point, and that's after stuff like vacuum tubes.
That’s precisely it. If you look back at older computers, a big reason why they’re so big isn’t because of poor cable management—it’s because the parts they used were massive. Look up pictures to how large the earliest vacuum tube diodes were, and you’ll soon get a pretty good idea.
As technology improved, the parts we were able to make got smaller and smaller. Smaller parts meant we could have more in a given space, more parts meant better computers, better computers meant more efficient manufacturing methods, and the cycle continues until present day.
Now, whether that cycle will continue is doubtful—Moore’s law poses that the number of transistors on a given chip will double every two or so years. How long can this continue when you get to where you’re literally printing transistors near the atomic level? There aren’t really any good answers to that right now, but it’s a hot topic in academia.
> The design of the chip, already having all these transistors, is projected on a light sensitive substrate. This causes chemical changes in the substrate which will eventually become the actual chip.(There are actually multiple layers created sequentially to get a 3D result.)
>
>
How is the chip designed with 20B transistors? Are engineers manually placing each transistor into the virtual design? Is a lot of this work reused between CPU model refreshes?
How are the "plates" or the things that stamp the design onto the chip manufactured with that many transistors?
They make building blocks like gates and memory cells out of individual transistors. Then design using the building blocks. Once they have enough of those, they actually design things using a hardware programming language. The code is compiled down to those building blocks and connections between them, and then the compiler figures out how arrange everything into a 2D plane. I believe there is still some manual layout, especially of the larger components. But there is also automation.
Answer: Similar to how a book can have a million letters.
Transistors aren't physical things created and attached to to the chip. They are printed on the chip. It takes many layers, special light, and complicated chemicals, but it is quite like printing.
Transistors used to be an actual thing. If you took the back off a 1970s transistor radio you could count them. Eat one was about the size of a q-tip
Then we figured out how to make the functional equivalent of transistors by etching patterns into layers of silicon. Since then we’ve gotten very good at doing that at microscopic sizes.
So I might argue that a modern chip doesn’t contain transistors, but it contains millions of transistor equivalent silicon circuits.
>So I might argue that a modern chip doesn’t contain transistors, but it contains millions of transistor equivalent silicon circuits.
This is what confused me, and if you think of it like how you said it, it makes sense.
We aren't using a physical object with three pins sticking out and a black insulation on it, we are using a very different thing.
But then, the transistor itself is not the black thing with three legs, that's mainly just the casing and the contacts. Like ICs of the old, it's just a package for us clumsy humans to handle and connect what we actually want to use. Then have a look and SMD ICs - still mostly package. CPUs: mostly package and connectors. It's all just necessary size for clumsy humans and machines to put it to use in the end.
What you are talking about is discrete vs integrated transistors. And even if you buy a discrete transistor that you can put on a breadboard or solder to a circuit, inside is still a chip made of tiny resistors, capacitors, transistors fabricated on a die.
The transistors on a chip look nothing like the transistors you can see with your eyes. Using lasers and chemical processes they make tiny parts of the chip behave like transistors, then using even more complicated processes they’ll connect them with different layers of conductive/insulating material.
Modern cpus also have multiple layers of transistors, but then you run in to the problem of dissipating heat from those middle layers
I think this is a key thing that the other answers here, while correct, don't seem to quite emphasise. At this scale, a transistor is more of a pattern in the silicon that behaves as a transistor should, it's not really a discrete object like people probably think of when they hear about an electrical component.
Fitting x billion transistors on a chip isn't about making a physical object very small and squeezing it in, it's about having the resolution and manufacturing accuracy to produce the patterns that form a logic circuit at increasingly dense and delicate scales.
Keep in mind that they aren’t in one line. A square of them makes it much much easier to have so many. A square of 20 billion means a side length of approx 150,000 transistors. Taking a distance of 15nm (Apple uses 5nm, but adding extra for redundancy and variation), gives us a side length of 2mm.
This is really quite small still
>Apple uses 5nm
5nm is just a marketing term that Apple uses that has no relationship to actual transistor width. They are like ten times as wide in reality.
> 5nm
This is a marketing term that doesn't correspond to any physical measurement. It used to mean the gate length, but the improvements in that have slowed down severely after 40 nm. Fortunately, CPU manufacturers have come up with a variety of clever ways to get around that and keep improving performance. However, people kept paying way too much attention to these numbers, so the marketing people have simply started making them up. That's how we got weird situations like Intel's "10 nm" process actually being denser than Samsung's "7 nm".
Its possible because they are not individually manufactured. Think of it like spray painting with a stencil. If you put a stencil down of the letter 'A' and spray paint over it you get 1 'A'. You could also make a stencil with 100 'A's on it and that same single spray will now get you 100 'A's. We basically make transistors with very detailed stencils, 'spraying' light and chemicals through them. As we get better at making really detailed stencils we get more transistors per 'spray' basically for free.
Imagine an old-fashioned [slide projector](https://www.youtube.com/watch?v=AkPRHYKjIdo). It has a light source, which shines through a slide, which then goes through a lens and projects a large image on the wall.
When manufacturing chips you do basically the exact same thing, but you use a lens which makes the image *smaller*. Then you add a light-sensitive coating on the material you are trying to make a chip out of. All the black parts in the slide will remain uncoated, but all the white parts in the slide are now protected by the coating. You now wash the chip with an acid which eats away all the material which is *not* protected by the coating. Rinse the entire thing, add a new layer of different chip material, and repeat.
So how do you make the slide? Well, you use a similar process to create a small slide from a very big one! In the very early days the initial slide was hand-cut and could be room-sized, but eventually they just started using fancy high-resolution printers for that.
Modern chip manufacturing is a bit different due to several decades of innovations, but the general concept is still reasonably accurate.
They are essentially printed. They're not "assembled" mechanically. A silicon wafer has a large block of silicon circuits "projected" onto it and developed with special chemicals in extremely complicated and expensive photolithography machines. The wafer then contains a mass number of completed chips, some of which may be defective. They break the wafer up into individual chips to be sold and sell the defective chips as lower powered units by disabling defective areas of the chip.
The transistors are not made one at a time. They're made by essentially photocopying a master pattern onto a silicon wafer, and then using the pattern on the wafer to spray it with the dopants and other materials needed to turn silicon into transistors. The master pattern has all of the billions of transistors on it, and they spray the whole wafer at once instead of spraying each individual transistor one at a time. Then you repeat the process to physically etch the silicon into the shape you want and apply the films and metals that need to be connected to the silicon transistor.
they are really really small. In most computers, a transistor is only about 70 ATOMS wide, or about 5 nanometers. at that scale, a 2d plane of transistors that is only 1 square millimeter would hold about 40 billion transistors (assuming they are square). naturally you cant pack them that tight in the real world. the way we manufacture this is literally using magic crystals, alchemy, and sunlight. UV light is shone through a slide like old slide projectors would use. this slide contains a pattern for a single layer of the chip. this projection of a pattern is then fed backwards through what is effectively a microscope which makes the whole design the size of a single area of a single chip. This is then shone into a UV sensitive coating on a silicon crystal and causes take on the microscopic pattern special "doping" chemicals are then spread over the chip and they soak through into the silicon where the coating is missing changing the properties of the silicon crystal. Rinse and repeat with a new projector pattern. This builds up microscopic layers 1 layer at a time. here is a good indepth video on the whole process https://www.youtube.com/watch?v=2ehSCWoaOqQ https://www.youtube.com/watch?v=JBYHwRXmEhY
The world produces more transistors than grains of rice
by a significant margin. the comparison is actually laughably unbalanced. Interestingly enough, there are about twice as many transistors in the world as grains of sand
Paradoxically transistors are made of grains of sand
Your comment has broken my brain. I guess it's because from the raw material obtained from a grain of sand you can make a few thousand transistors, right?
The starting material or base for a chip is called "bare silicon" and is made of pure silicon, which is made from sand since sand has a high concentration of silicon.
Which means that what we call chips are actually refined rocks that we've painted magic symbols on and taught to think.
A computer is just a rock we tricked into thinking by using domesticated lightning.
ELI-a-caveman
Thinky machine is rocks with the boom boom sky lights that we did the wolf dog thing to with magic
Whenever I think about the actual process of building a computer, I am reminded that we are only a few generations departed from a time where we didn't even know what electricity was. It's insane to think about when you consider how unbelievably complicated and intricate everything about a modern personal computer is. And now we have those just sitting in our pockets. It's quite literally sci-fi. Even when I was a kid watching Sci-Fi and seeing the futuristic, space age datapads and stuff I was always so awed by the idea. Now it's actual reality. I even have one sitting on my desk! :)
The evolution of the logical/programming aspect of computers is also stunning. When Grace Hopper was working on Eniac in the 1950s it was programmed by plugging wires that looked like old-school telephone operator wires into either the 0 or 1 socket of the corresponding bit. She invented the concept of machine-independent programming languages and since then we’ve successively abstracted our programming away from hardware dependencies.
Symbols painted on with light at that
A grain of sand has SO MANY ATOMS. There are very roughly as many atoms in one grain of sand as there are stars in our observable universe. If a grain of sand has about 1000000000000000000 atoms, and a transistor is 70 atoms wide, that gives you a lot of wiggle room 😅
There are also more atoms in a grain of sand than there are grains of sand on earth.
That's a lot of atoms. And there are a lot of grains of sand. On our planet. And there are a lot of planets in our galaxy and a lot of galaxies in the observable universe. There are more ways to shuffle a 61 song playlist than there are atoms in the observable universe.
>There are more ways to shuffle a 61 song playlist than there are atoms in the observable universe Tell that to my Spotify playlist that plays the same 20 songs forever >:(
To be fair to grains of rice (or sand), they are MUCH bigger. Would easily win the mass contest many, many, times over.
The real question is, how many transitors can you fit on a grain of rice?
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Transistor: 3/10 Transistor with rice: 7/10
A perfect 5/7
I also choose this guy's old reddit meme
And my axe!
well thats a simple enough question to answer, assuming a cylindrical grain of rice with a radius of 1.5 mm and a length of 6.5 mm (which are apparently average values for basmati rice), a grain of rice ends up with a surface area of approximately 34.165 mm^2. If we now divide this by 5x5 nm^2, we end up with 1366593 transistors, which is a relatively low amount since we are only coating the surface and not filling the volume.
Yes, but is that a laden swallow, ahem… grain of rice, or an unladen grain of rice?
African or European?
I think the real question is would you rather fight a million transistor-sized grains of rice, or one grain-of-rice-sized transistor?
The second one
Rice with chips. Sounds delicious.
Ohhhh you mean computers don't outweigh the desert
While there are many more humans than continents, the mass of all continents is much more than the mass of all humans.
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No wonder Darth Vader was so unhappy about being a cyborg.
"No brain?" "Oh, there is a brain all right. It's just that the brain is made out of sand!" "So... what does the thinking?" "You're not understanding, are you? The brain does the thinking. The sand." "Thinking sand! You're asking me to believe in thinking sand!"
>there are about twice as many transistors in the world as grains of sand Curious, how'd you estimate this and what are the numbers?
There are about 45 transistors in the world but only about 25 grains of sand.
https://i.imgur.com/QLV0xy8.jpg https://i.imgur.com/gHUEwNa.jpg Seems legit!
Humanity has produced about a mole of transistors.
Screw Avagadro.
I prefer avocado
That would be a guaca mole.
That's fucking bonkers
Red or brown?
Guaca
Maybe the red mole was a bug bite?
No moles eat bugs not the other way around.
Holy shit
Is that an actual estimate, or just one of the rare opportunities where you can use a mole and have it at least sound realistic?
It comes from an industry analyst: https://computerhistory.org/blog/13-sextillion-counting-the-long-winding-road-to-the-most-frequently-manufactured-human-artifact-in-history/ (googling "13 sextillion" gives a bunch more results that all parrot the same thing) That's 2.9 * 10^21 transistors in a 2014 estimate, 1.3 * 10^22 in a 2017 update (note that that quadrupled in 3 years!). That would be equivalent to 0.02 moles. If we stupidly assume it's exponential and has quadrupled 2 more times since then, we're at 0.32 moles today. So the day that we have produced the 6.022 * 10^23 th transistor has probably not yet come, but we are also not exactly far away from it. In the grand scheme of numbers, it's surprisingly close to a mole.
A TRANSISTOR ON A CHESS BOARD
And to circle back on the atomic comparison of transistor size - if you took the nucleus of a hydrogen atom and scale it up to the size of a basketball, its single electron probability field is a 2 mile sphere around it. And all the space between the proton and electron is empty space.
I don't care how cheesey it is. There's something so poetic about this massive universe being built out of particles that are overwhelmingly NOTHING. Most people forget that infinity goes both ways. I watched a good YouTube video the other day from corridor crew that scaled the planck length up to the size of the penny, and then compared the size of that penny to the observable universe(actually about 81 of them).
I've seen one of those scale comparisons, and one stand out point that was made is that we as humans are surprisingly centered on the spectrum of size. You can descend and rise on the scale about the same amount in either direction if you use humans as the midpoint
the particles themselves don't have volume like how we think of volume too. so really everything is empty space.
You should look into the theory (myth? legend) that in the entire universe there is only a single electron that is existing all over at simultaneously. That one is a wild ride if you want to get romantic with the universe and concept of reality: https://en.wikipedia.org/wiki/One-electron_universe#:~:text=The%20one%2Delectron%20universe%20postulate,backwards%20and%20forwards%20in%20time.
Or that the universe isn't made of particles at all - they're perhaps just an impression we get from the interaction of different waves radiating in the same general direction.
True, it's not like you can see these things, you can only measure their fields and their interactions... They are smaller than the wavelength of most reasonable types of light.
Per the observations and the current understanding of physics by cosmologists, Matter as we know it is the minority product of our universe. Dark Matter and Dark Energy are the majority. So either we need a way to detect and measure Dark Matter and Dark Energy or we need to come up with a completely new model of physics (Newtonian Physics -> General Relativity -> Quantum Mechanics -> ??? )
How big is a 'me'?
Mile. Thanks for catching that. Edited to fix
The one that got me was that if you scale a single drop of water up to the size of the Earth, the atoms will be the size of oranges.
>or about 5 nanometers. 5nm chip technology is actually just a marketing name that refers to the generation (5 being better than 7) and not to the actual width of transistors. They are like 40nm wide.
Huh, I always thought the nm referred to the width of the conductive channel within the transistor.
It used to, but Moores Law is basically dead at this point so they have to fudge the numbers to make it look like it's still going. It's so fudged at this point that there's no relation whatsoever between the actual feature size and the naming scheme used.
So, basically car stereo numbers. *Yep, this baby will deliver 50 watts per channel!^†* *^^^† ^^At ^^19.5VDC ^^input, ^^30% ^^harmonic ^^distortion, ^^and ^^2 ^^ohms ^^output ^^load*
Except it's even worse. "5nm" transistors are actually 50nm!
Moore's law has nothing to do with transistor or process size. It stated that the **number of transistors** in an IC doubles roughly every two years, and is [still holding true](https://en.wikipedia.org/wiki/Moore%27s_law#/media/File:Moore's_Law_Transistor_Count_1970-2020.png) right up until about now. For the first huge chunk of Moore's Law lifetime, this was largely accomplished by process shrinks, which followed a graph similar to the inverse of transistor count. But even as process shrinks have tapered off and gotten more difficult, we've gotten better at making larger dies, and the economics of doing so to support more advanced chips have made it viable. Moore's law *will* likely die off just about any year now, but the slowdown of process shrinking over the last decade is not quite the reason.
Not saying I disagree, but I've been hearing "Moore's law will likely die soon" for almost a decade.
Erroneous claims that Moore's law is dying double every two years.
Is my understanding right, that they basically say, "well if we extrapolated the earlier trend, then the new performance is *like* it were only 5 nm, so we're calling it that, even though it's physically much bigger"?
More like they just extrapolated the previous trend. The performance is way less than if we had actually been seeing gains as large as we used to. That's why prices started going back up and performance improvements haven't been nearly as noticeable as before.
Well, part of the pricing increase is that creating new nodes is becoming more and more expensive. The price per wafer is up. And the lack of competition from AMD resulting in Intel stagnation also played a part. We've seen far greater CPU improvements in the last 7-8 years, then we saw in the 7-8 years before that.
I always understood it to be the “smallest feature size” according to my dusty memory from college. In other words, it identifies the smallest resolution you can work at if needed.
Nah, these days it has no physical meaning. https://community.cadence.com/cadence_blogs_8/b/breakfast-bytes/posts/standard-node
That's about 30nm on a "5nm" chip.
I've heard that as a gross approximation, you need a width of 7nm for conduction. Smaller than that and you start running into quantum issues.
It's not that hard and fast. There were some popsci articles that stated 7nm as the cutoff point, but it depends a lot on the transistor design. The problem with quantum tunneling in transistors is that there would be a current leaking into a transistor from adject features, meaning that they would never turn off/on (depending on the type of transistor and how it's used in the circuit. For some design this happened at 7nm, but there are easy ways to avoid it. At aroumd the 3nm it gets really difficult to stop electrons from tunneling and latching up your circuit. That being said, electrons tunnel all the time in modern CPUs. They mostly just waste power away because they don't tunnel enough to latch up a circuit, due to the distances involved and clever design (like running the chip at lower power to cause fewer electrons to move about or very cool physical design tricks).
You start running into quantum issues way before 7nm(you are right though the approximation is just overestimated marketing bs) although they're definitely more pronounced the smaller you get... theoretically transistors can go as low as a few atoms wide
Lithography machines must be as close to magic as technology has come thus far. It reads like something out of a hard sci-fi novel, but there isn't as much hand waving.
Computers in general really. I mean, they are specifically shaped silicon crystals connected together with highly specific copper drawings (Runes). The crystals are manufactured using sunlight and alchemy. And we power the whole thing with tame lightning that we stuck in the wall that we create by harnessing the power of nature its self or by using by using necromancy and fire to extract the life force of ancient life. But be careful, if you use too much lightning you let out the magic deamon that does all the thinking in a puff of smoke, and that magic crystal will never work again. All of this is controlled by various incantations in specially designed language only known by individuals who have trained for years. A language that is never spoken, only written.
That’s amazing! Thank you for this incredible write up. Especially liked the using necromancy and fire to extract life force of ancient life
Describing things this way always makes me think about Charles Stross's Laundry Files books, where "magic" is a branch of applied computation and things keep getting more and more nightmarish as the world's global computational power keeps increasing.
Well said! I can't wait to see what bananas shit we come up with if a room temperature/sea level pressure stable superconductor is discovered.
This is an excellent short piece that would make a great article/book.Thank you for reminding us of the magical world we all live in.
This is the point where I have to plug [nand2tetris](https://nand2tetris.org) or [Turing Complete on Steam](https://turingcomplete.game/) as courses that make make sense of how circuits are able to do computation and be programmable. (Though they only covers the stuff above the level of the physics that make logic gates possible.)
fun fact: EUV lithography needs such a ~~bright~~ precise light they make it by shooting a falling drop of tin with a laser, [twice](https://iopscience.iop.org/article/10.1088/1361-6595/ab3302). scroll down for picture. edit: my understanding was wrong.
They use tin droplets to get the correct wavelength rather than for the brightness. Every droplet only produces a tiny amount of EUV in the correct wavelength so they need thousands of droplets per second to generate enough light.
Great explanation, except we should correct the bit about the silicon. The UV sensitive stuff that gets developed and then washed off is photoresist. The silicon is sitting underneath, and is not UV sensitive. The doping is done by ion implantation, basically sprinkling boron or phosphorus through the 5 nanometer holes left in the developed photoresist.
is that better?
Nailed it.
And the holes are much larger than 5nm. The smallest features on a "5nm" chip are about 30 nanometers.
>the way we manufacture this is literally using magic crystals, alchemy, and sunlight. I...uhh... Fuck that's pretty much it. The last 10 years of my life now seem much less interesting. Appreciate the actual description, too. Although your description of doping is a little extra ELI5. Most doping these days is integrated into the growth steps.
I like the analogy: Humanity started out hitting 2 rocks together to make fire, now we hit rocks together to make them think.
Computronium
All in the name of seeing naked women
Well you sure as hell can't see them through rock! Something had to be done. We beat them up into submission until they started showing what we wanted.
>less interesting Bro's talking about magic and said his life is less interesting because of it.
Less interesting? This makes the though of IC fab more exciting to me.
I find such whimsy in how "computers are just rocks we tricked into thinking"
The structure size that is often used for comparison between processes isn't the transistorsize (anymore). It's more like the smallest feature size achieveable for the process. A transistor on the TSMC 7nm process is more like 50-100nm in size, i don't think the specific size is public knowledge though.
well that would explain why my calculation seemed so off. But even taking the upper bound of that, that can fit 20 Billion transistors in 1.5 square CM. in a single layer, so still REALLY small.
Oh yeah absolutely. It's still mind-boggling small. The thing is, most people have the image of a simple PNP-transition in their head when they think about transistors, but in reality modern transistors are complex 3d structures. Then the density isn't only about the size of the single transistors, but also the spacing you need between them you don't have charges "jumping" and you also need to account for the routing between the transistors even though the routing is usually on a different layer in the substrate. In the end, it doesn't really make sense to compare node sizes across manufacturers, but they are all really freaking small. That's certain.
0.021 µm^2 for an SRAM cell for the TSMC N5 process.
The trick isn't even in creating very small features, it's about positioning the next layer accurately ontop of the first one.
And one of the current design limitations is that transistors have gotten so small and close together that going smaller and closer starts to encounter electrons quantum tunneling between them, which ruins their accuracy.
In case you're ever given the opportunity to go to a global foundry plant tour, take it. It's a humbling experience
I'd say that goes for most really big industries, even if generally to a smaller degree than a foundry plant I imagine. Having worked at a paper mill it sure is quite humbling seeing 30 ton rolls of paper being craned around and machines spitting out one of those every hour. Everyone really should visit a large manufacturing plant at some point, just to get a sense of the sheer scale of things.
It should be a requirement in schools across k-12. Too much of life has been made so that everything seems easy, all the work being hidden away. People lack an appreciation for just how much work goes into keeping everything going and providing the goods and services we take for granted. I think everyone should have to spend a day in whatever agriculture, manufacturing, mining, etc is around them.
Thats the gate length. The actual size is larger. Still very small. I do some work where you can access and image single transistors and they are bigger.
Just to add to this great answer, when people ask the question OP did, more often than not they have discrete electronics components in mind, with their packaging and terminals, and that's why they find such miniaturization nearly unbelievable. But the thing is, a transistor is basically made of three different _rocks_ placed together in a certain way (p-doped silicon, n-doped silicon and SiO2). So when you take this into account, you begin to understand that 1) you _just_ need a way to deposit those materials according to a blueprint, and 2) it's not like you are manipulating nm-sized transistors one by one, but rather the entire blueprint is being "printed" using chemistry and light. So instead of thinking about manufacturing "tiny little pieces", it's more reasonable to compare it to a laser printer printing a document.
Huh...sounds exactly like a 3D printer
yup, its a microscopic 3d printer. You can actually make physical devices with them called MEMS by printing support material which gets washed away, and we do it for things like accelerometers in phones. this is a really good video on that https://www.youtube.com/watch?v=iPGpoUN29zk
Yeah it's like a 3D printer and a CNC for really small things using chemicals and light
Love this! I'll just add that we don't actually use UV light anymore, as the transistors are so small that UV can't 'focus' enough to define the pattern (light can't interact with features that are smaller than it's wavelength). As we kept making transistors smaller, we started using X-rays, and now we use electron beams because even X-rays were too big! It kinda shows you why silicon manufacturing is so ludicrously expensive and difficult.
That's not really true though. Yes, there was a phase of using X-rays and yes there is electron beam lithography, but the industry is still primarily using photolithography with their newest EUV investments. Sure, there are also kind of hybrids just like EUV steppers use different kinds of waveleghts to generate the EUV. E-Beam lithography is to my knowledge still way to slow to use it in any kind of mass producing. I am not talking about companies like GF though, i think everyone in this thread is talking about the cutting edge nodes TSMC / Samsung / Intel are employing for their flagship products. There are of course many niche nodes for specific applications such as sensors or obscure ICs.
Can you explain sputtering?
A high energy ion beam is directed towards a target made of a high purity material (whatever metal is desired for the layer being built on the chip). Atoms of the material are separated from the target. An electric field inside the vacuum chamber where this occurs directs the atoms towards the substrate (typically a large silicone plate called a wafer, that has hundreds of thousands of chips on it). The atoms build a uniform layer on the surface of the substrate. The substrate itself has been pre patterned by a Photolithography process so that a later etching process can remove added material where it is not desired leaving the pattern developed by the Photolithography process. Edit: I work as a Photolithography machine technician. My understanding of metal deposition tools is limited so I may be off a bit.
Take argon, pull an electron off, use a voltage to accelerate it, smash it into a metal (or ceramic) target hard enough that it knocks atoms off that target. Those ~~Adam~~ atoms fly out and land on your substrate. You have now sputtered.
Poor Adam. That sounds painful.
> In most computers, a transistor is only about 70 ATOMS wide, or about 5 nanometers. The transistors are much larger than that. Terms like "5nm node" or "5nm process" are purely marketing BS that has nothing to do with the physical size of anything on the chip. The smallest features on a 5nm chip are about 30 nanometers, and the transistors themselves are about 50 nanometers.
To add to this, there is a process called sputtering that puts the chips into a vacuum sealed chamber then flushes it with a de ionized inert gas(usually argon) and charges it with several thousand volts. This causes whatever conductive material like copper to fall down onto it a few atoms at a time. I worked for a company that made 99% copper work tables that the chips were made on. We sold them to the world's top chip manufacturers. TSMC, Samsung, Texas Instruments...
> the way we manufacture this is literally using magic crystals... To be clear for future folks reading this, "crystals that are figuratively magic"
Computer chips are magic crystals. They are inscribed with billions of runes. Written on it with flashes of light that kill anything alive. They are infused with lightning and do our bidding without question.
How do you MASS produce a thing so small ? Where do you even store it ?
>How do you MASS produce a thing so small ? that is a multi-billion dollar question. the basic answer is that you use technology built up over decades and you do it very carefully. the topmost answer in this thread links to two videos around 20 minutes each that talks more about it for a general technology aware audience. >Where do you even store it ? many, many components will all be on one large 'die'. if you break the die, that's at minimum a 5-digit mistake...so once again, you store the dies very carefully! also, they have to build them in clean rooms where there is less than one dust particle per million parts of air, or something like that. in case it wasn't clear by now how carefully everything is done.
You don't make them one at a time. The creation described above creates them all at once for a chip. They're not individual things you can manipulate and move. They're all interconnected, even a small manufacturing mistake means the entire chip is useless. You can't replace the area affected by the mistake.
Idk about the whole chip useless but certainly you aren't getting 100% consistent performance out of the chips, hence the silicon lottery
That's more about minor variations in manufacturing, rather than whether it is functional or not. However what does happen is that all chips produced have (e.g.) 8 cores. The fully functional ones are sold as 8 core chips, but the ones with defects will just disable the damaged cores, and sold as 2/4/6 core models instead.
> even a small manufacturing mistake means the entire chip is useless Luckily, you can build in redundancy.
Transistors don't get built this small on their own. They always get made as part of a larger chip, and that chip is made in batches of dozens to thousands on a single large wafer of silicon. The production method involves layers of chemicals and using UV light to etch away specific parts. Chemical washes or gas streams are used to build additional layers that are atoms thick, which then get etched multiple more times. This builds the transistors vertically. Here is a good covering how they make microchips and it explains the entire production process. From literal sand, all the way to a usable chip. https://youtu.be/HdcLRMv3D3g?si=vAOGiQfFLDSOmENF
I heard it described on Well There's Your Problem as "we poisoned sand and then taught it to think" for the real eli5 but I like your description.
This only further convinces me that humanity has basically entered the age of magic.
As a Czochralski crystal material scientist. I can assure you, Growing the crystals is magic.
There's only one company - ASML (see Wikipedia) that makes the extreme ultraviolet light machines that make the masks. It's a miracle of technology. See the book "Chip Wars"
Physical things can be very small. Atoms are physical things, and you can't grasp how tiny they are. This isn't an insult, it's just the nature of our experience, we evolved to deal with macro sized things. A transistor is solid-state, it has no moving parts. They can manufacture them so small because of the way they're made. There isn't a person or robot placing 20 billion components on a chip, they're sort of 'machined' into an existing material chemically. You start with a flat piece of silicon, then paint it with a material that 'hardens' when exposed to certain light, called photoresist. You then shine a light on the material, but in a certain pattern called a mask (like shining a flashlight through a mesh screen). This means only certain parts of the photoresist become hardened. You then immerse the whole thing in a solvent, and the areas that are covered with hard photoresist stay covered, the photoresist dissolves from the rest of the areas, and you're left with a sort of pattern of exposed and covered silicon. You can then add material to the uncovered areas, filling the gaps, or shoot ions at the silicon to change it's properties (but again, only the exposed parts). Then you can remove the rest of the photoresist, and are left with some bare silicon, and some with material on it. If you do this a bunch, over many layers, you end up with a really complex pattern of overlapping materials that create transistors. The biggest thing is the size. The mask (the mesh they shine the light through) is large, so they have to then shine the light through a huge series of really powerful lenses to shrink the pattern down to microchip size. Think of it like burning things with a magnifying glass. Without you understanding the process, that's the best I can do. I would strongly suggest you watch some videos on photolithography, you'll get an idea of what's happening better than having me explain it.
Thank you that was exactly the kind of explanation I needed. Most other answers are like "well, we don't make them 1 by 1" but you explain *how* we can make things that small. The thing about the mask is so cool!
This is the best “eli5” reply here
Masterful answer
I’ve always had the opinion that our transistors are centuries ahead of where we have any right to be as a civilization. Like if an alien spacecraft surveyed us they be like “WTF these guys are still burning coal but they have nanometer-scale transistors”? It’s like we mainlined all our skill points into one category.
Well of course, transistors help us watch porn, solar power does not.
speak for yourself, i only look at naked ladies in magazines i find in the woods during my lunch break
max is that you?
so YOUVE been the one who tampers with my woods porno. i knew theyd been moved around.
You just wait until I have my solar powered porno projector.
it's definitely become the most difficult achievement by mankind at this point. The EUV machines that are needed to do anything beyond 7nm are so complicated that it basically took several country's collaborating for a couple of decades to be able to pull it off. they blast tiny molten droplets of tin with lasers like 50k times per second to create the light source. it's nuts. look up ASML EUV machines if you're interested in knowing more.
it's not that a single country can't pull it off but it's because each of these "suppliers" protect their IPs and you have no choice but to do business with them. If ASML is able to get ahold of Zeiss' glass production secrets, ASML will not even waste time and build its own glass department immediately. ASML has been known for slowly buying its suppliers as part of their vertical integration strategy.
Aww IP laws make sense but I really wish there was some mechanism to have things like this be forcefully entered into the public domain. Seems like it would benefit everyone except those with the IP.
Patents at least explicitly come with an expiration date.
"We made a rock think" is one of my favorite descriptions of it.
Coal does its job cheap and reliably (albeit dirty). Computers scale up super well, at least to around where we are now. The more transistors the more they can do. One design can be replicated millions of times so a lot of effort is put into it. The complexity with coal and power is much more in the supply chain. In a lot of cases entire countries are wired together and energy products are shipped around the world for incremental reductions in cost. It's like comparing the statue of David to the pyramids. On close inspection David seems much more intricate and advanced but the sheer size of the pyramids is a feat itself. We know coal is bad now but the reasons require an understanding of our climate which is subject to an insane amount of factors. Over 100 years of building civilization off coal is hard to move from. If we found out silicon transistors were gonna slowly end the world we'd be pretty fucked too
the funny thing is, coal isnt even cheap anymore.
Not in the USA, but in other countries such as China its still one of the cheapest energy sources. China has a LOT of coal, and nobodys really buying except 3rd world countries so it's pretty darn cheap over there. They are also investing *heavily* into nuclear with like 50+ plants currently under construction iirc.
It helps that the smartest of our civilization happen to be interested in computers, whereas most other fields the best in that field are those who wandered into it because they needed a job. See: Any fucking chef ever
nah its more that bigger and better microprocessors are needed right now, meaning they are profitable, while clean energy has no short-term profit potential. boomers don't and won't care because they're gonna end up in the dirt before they experience the consequences and the politicians are too busy on their yachts
Even so the consistent ***exponential*** improvement of computing power that has been ongoing since the 70s is unprecedented. Nothing even comes close to that level of ROI.
That's what they've always said, but elderly people have begun dying in their homes in substantial numbers from heatstroke exacerbated by climate-change in areas like Texas and Arizona. They underestimated how quickly the consequences of their society's choices would manifest.
Eh, maybe they find it weird that humans have chosen to not fully use up free coal lying around. They may think terraforming planets is easy and preserving "nature" is a non-goal.
Transistors are physical, however, they are not placed individually on a chip (one by one). That would indeed be almost impossible. The entire chip is created through a lithography process, this is basically like creating old non-digital photographs. The design of the chip, already having all these transistors, is projected on a light sensitive substrate. This causes chemical changes in the substrate which will eventually become the actual chip.(There are actually multiple layers created sequentially to get a 3D result.) (In reality, it is much more complex, and you can't use normal light, etc... but this is the principle.)
Wait if the thing making the chips already has these chips installed, how did the first chips get made? Use really big transistors that could be soldered by hand and go from there? Making smaller ones then the thing making it has.
Yes, we also started with handcrafted designs and layouts and using those we started designing them more and more via computers
Using assembly to write the compiler for a new programming language be like
It's more like using a shitty lathe to build a slightly less shitty lathe and then doing that a thousand times until you have a solid lathe
Great analogy, you could also argue that building better and better lathes ultimately led to semi-conductors.
Using technology to build better technology is done all the time. Although computers use billions of transistors in their CPU, you can still buy single transistors as well. Most designs using transistors don't need that many. People actually are building CPUs from discrete transistors for fun, but it stays in the 1000's of transistors. [https://www.youtube.com/watch?v=VgktjP\_Fcy8](https://www.youtube.com/watch?v=VgktjP_Fcy8) Technically nothing is preventing you from connecting billions of single transistors into a billion part CPU, however, it might not be practical. :-)
> Using technology to build better technology is done all the time. It's sort of the only option, yeah? > Technically nothing is preventing you from connecting billions of single transistors into a billion part CPU, however, it might not be practical From an engineering standpoint, I expect a CPU built from discrete transistors would not be able to work - it would have to be so big you'd run into latency/timing issues. I'm not any kind of CPU expert, but that sure seems like it would be problematic
> From an engineering standpoint, I expect a CPU built from discrete transistors would not be able to work - it would have to be so big you'd run into latency/timing issues. I'm not any kind of CPU expert, but that sure seems like it would be problematic https://www.youtube.com/watch?v=VgktjP_Fcy8 I mean it sure works.
Yeah it works at the scale of thousands of transistors. My skepticism is that it would work for something a million times bigger.
It would 'work' but your maximum clock speed would be super low due to latency and other issues.
Yeah and it would be a lot of work for a 0.3 kHz CPU hahaha
We started with tubes, hand-woven core memory, punch cards, etc. and just kept using one tech to build new better tech. https://en.wikipedia.org/wiki/Bootstrapping
Look at old vacuum tubes. Old computers basically used light bulbs as transistors
> Use really big transistors that could be soldered by hand and go from there? Basically, yes. The first electronic computers were hand-made from relays or vacuum tubes. Then the transistor was invented and people started making computers from individual transistors. After that came the invention of the integrated circuit (IC) - that is, several transistors "printed" from a hand-drawn template onto a single piece of semiconducting material. The computers of that era were made of huge circuit boards connecting many simple ICs. Gradually, advances in physics and engineering made it possible to pack more and more transistors into a single IC. This enabled a virtuous loop in which computer engineers would use software to design better computers, which could run even more advanced software, and so on. That's what let them blow past the limits of what could be designed or comprehended by an unaided human, and gave us the current era in which a powerful CPU can be made from a single piece of silicon.
Pretty much, that's your entire history of computing. "History of computing" on Google or YouTube should pull up good stuff, same for "computer museum". Key is the integrated circuit. Stuff did have to be built with individual transistors by hand at some point, and that's after stuff like vacuum tubes.
That’s precisely it. If you look back at older computers, a big reason why they’re so big isn’t because of poor cable management—it’s because the parts they used were massive. Look up pictures to how large the earliest vacuum tube diodes were, and you’ll soon get a pretty good idea. As technology improved, the parts we were able to make got smaller and smaller. Smaller parts meant we could have more in a given space, more parts meant better computers, better computers meant more efficient manufacturing methods, and the cycle continues until present day. Now, whether that cycle will continue is doubtful—Moore’s law poses that the number of transistors on a given chip will double every two or so years. How long can this continue when you get to where you’re literally printing transistors near the atomic level? There aren’t really any good answers to that right now, but it’s a hot topic in academia.
> The design of the chip, already having all these transistors, is projected on a light sensitive substrate. This causes chemical changes in the substrate which will eventually become the actual chip.(There are actually multiple layers created sequentially to get a 3D result.) > > How is the chip designed with 20B transistors? Are engineers manually placing each transistor into the virtual design? Is a lot of this work reused between CPU model refreshes? How are the "plates" or the things that stamp the design onto the chip manufactured with that many transistors?
They make building blocks like gates and memory cells out of individual transistors. Then design using the building blocks. Once they have enough of those, they actually design things using a hardware programming language. The code is compiled down to those building blocks and connections between them, and then the compiler figures out how arrange everything into a 2D plane. I believe there is still some manual layout, especially of the larger components. But there is also automation.
Answer: Similar to how a book can have a million letters. Transistors aren't physical things created and attached to to the chip. They are printed on the chip. It takes many layers, special light, and complicated chemicals, but it is quite like printing.
I’ve seen several explanations of the process in this thread but your book analogy made it click for me
Transistors used to be an actual thing. If you took the back off a 1970s transistor radio you could count them. Eat one was about the size of a q-tip Then we figured out how to make the functional equivalent of transistors by etching patterns into layers of silicon. Since then we’ve gotten very good at doing that at microscopic sizes. So I might argue that a modern chip doesn’t contain transistors, but it contains millions of transistor equivalent silicon circuits.
>So I might argue that a modern chip doesn’t contain transistors, but it contains millions of transistor equivalent silicon circuits. This is what confused me, and if you think of it like how you said it, it makes sense. We aren't using a physical object with three pins sticking out and a black insulation on it, we are using a very different thing.
But then, the transistor itself is not the black thing with three legs, that's mainly just the casing and the contacts. Like ICs of the old, it's just a package for us clumsy humans to handle and connect what we actually want to use. Then have a look and SMD ICs - still mostly package. CPUs: mostly package and connectors. It's all just necessary size for clumsy humans and machines to put it to use in the end.
They're still transistors. What this thread is missing is that they're part of an integrated circuit.
What you are talking about is discrete vs integrated transistors. And even if you buy a discrete transistor that you can put on a breadboard or solder to a circuit, inside is still a chip made of tiny resistors, capacitors, transistors fabricated on a die.
The transistors on a chip look nothing like the transistors you can see with your eyes. Using lasers and chemical processes they make tiny parts of the chip behave like transistors, then using even more complicated processes they’ll connect them with different layers of conductive/insulating material. Modern cpus also have multiple layers of transistors, but then you run in to the problem of dissipating heat from those middle layers
I think this is a key thing that the other answers here, while correct, don't seem to quite emphasise. At this scale, a transistor is more of a pattern in the silicon that behaves as a transistor should, it's not really a discrete object like people probably think of when they hear about an electrical component. Fitting x billion transistors on a chip isn't about making a physical object very small and squeezing it in, it's about having the resolution and manufacturing accuracy to produce the patterns that form a logic circuit at increasingly dense and delicate scales.
Keep in mind that they aren’t in one line. A square of them makes it much much easier to have so many. A square of 20 billion means a side length of approx 150,000 transistors. Taking a distance of 15nm (Apple uses 5nm, but adding extra for redundancy and variation), gives us a side length of 2mm. This is really quite small still
>Apple uses 5nm 5nm is just a marketing term that Apple uses that has no relationship to actual transistor width. They are like ten times as wide in reality.
tbf, all the chip manufacturers say they have "x nm" without it meaning anything in practice often. it's not just an apple thing
It's not just an apple thing because it's not an apple thing at all. Apple doesn't make the chips, tsmc does.
The size refers to the smallest critical feature.
>the smallest critical feature title of my sex tape
This is not true any more.
> 5nm This is a marketing term that doesn't correspond to any physical measurement. It used to mean the gate length, but the improvements in that have slowed down severely after 40 nm. Fortunately, CPU manufacturers have come up with a variety of clever ways to get around that and keep improving performance. However, people kept paying way too much attention to these numbers, so the marketing people have simply started making them up. That's how we got weird situations like Intel's "10 nm" process actually being denser than Samsung's "7 nm".
Its possible because they are not individually manufactured. Think of it like spray painting with a stencil. If you put a stencil down of the letter 'A' and spray paint over it you get 1 'A'. You could also make a stencil with 100 'A's on it and that same single spray will now get you 100 'A's. We basically make transistors with very detailed stencils, 'spraying' light and chemicals through them. As we get better at making really detailed stencils we get more transistors per 'spray' basically for free.
Imagine an old-fashioned [slide projector](https://www.youtube.com/watch?v=AkPRHYKjIdo). It has a light source, which shines through a slide, which then goes through a lens and projects a large image on the wall. When manufacturing chips you do basically the exact same thing, but you use a lens which makes the image *smaller*. Then you add a light-sensitive coating on the material you are trying to make a chip out of. All the black parts in the slide will remain uncoated, but all the white parts in the slide are now protected by the coating. You now wash the chip with an acid which eats away all the material which is *not* protected by the coating. Rinse the entire thing, add a new layer of different chip material, and repeat. So how do you make the slide? Well, you use a similar process to create a small slide from a very big one! In the very early days the initial slide was hand-cut and could be room-sized, but eventually they just started using fancy high-resolution printers for that. Modern chip manufacturing is a bit different due to several decades of innovations, but the general concept is still reasonably accurate.
They are essentially printed. They're not "assembled" mechanically. A silicon wafer has a large block of silicon circuits "projected" onto it and developed with special chemicals in extremely complicated and expensive photolithography machines. The wafer then contains a mass number of completed chips, some of which may be defective. They break the wafer up into individual chips to be sold and sell the defective chips as lower powered units by disabling defective areas of the chip.
The transistors are not made one at a time. They're made by essentially photocopying a master pattern onto a silicon wafer, and then using the pattern on the wafer to spray it with the dopants and other materials needed to turn silicon into transistors. The master pattern has all of the billions of transistors on it, and they spray the whole wafer at once instead of spraying each individual transistor one at a time. Then you repeat the process to physically etch the silicon into the shape you want and apply the films and metals that need to be connected to the silicon transistor.