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▲ Diamond Transistor(df.com)
113 points by Gravityloss 3 days ago | 61 comments
▲TGower 6 hours ago | parent | next [-]

It still amazes me that the rare shiny rocks humanity has appreciated for thousands of years also turn out to have amazing properties even compared to the synthetic materials we are now capable of creating. It's still the hardest material we have measured. It is the best thermal conductor, even though it's an electrical insulator.

▲Waterluvian 5 hours ago | parent | next [-]

I've thought about this at times. How convenient that things seem to work out that way! Though I wonder if it's more just a bias. All the very impressive things you can make from the abundant materials have already been made. Like, say, all of life?

▲ACCount39 4 hours ago | parent [-]

Blue pigments used to be extremely rare and precious. Then some chemists found the infinite blue glitch.

▲Waterluvian 3 hours ago | parent [-]

Also the convert energy into aluminum glitch.

▲numlock86 2 hours ago | parent | prev | next [-]

> even compared to the synthetic materials we are now capable of creating

Aren't like almost all commercially used diamonds these days synthetic as well? As far as I can tell, other than just for the sake of them being "natural" or for having weird impurities that add color to them (read as: subjectively better to some people), no one wants/needs natural ones anymore.

▲kulahan an hour ago | parent [-]

We can recreate lots of things, but almost always appreciate the true version better. It’s why it’s cooler to see the Mona Lisa than to see a poster print of it.

Why? As far as I can tell, other than just for the sake of the view being “natural” or having some weird color issues due to time and radiation and oxidization, nobody wants/needs the actual painting anymore.

Reason: because even when it’s identical or even inferior, the touch of nature is just… nice.

▲MengerSponge 6 hours ago | parent | prev | next [-]

It is a very good thermal conductor, but not the best. At low temperatures, copper is better. At very low temperatures, helium is much better.

Superfluid helium's maximum thermal conductivity is roughly 100x diamond's maximum!

▲hyperhello 5 hours ago | parent | next [-]

Neat! At around the temperature of liquid water, it's still about five times as good as copper.

▲FuriouslyAdrift 2 hours ago | parent | prev | next [-]

They make nice (and expensive) tweeters, too.

https://www.madisoundspeakerstore.com/diamond-dome-tweeters/...

▲jcims 4 hours ago | parent | prev [-]

>Superfluid helium's maximum thermal conductivity is roughly 100x diamond's maximum!

Never thought about this before. Would that mean that heat propagates much more quickly? Possibly even approaching the speed of sound of the material?

▲meindnoch an hour ago | parent | next [-]

Thermal conductivity measures the heat flux given a temperature gradient. That is, how fast heat energy flows across a surface, given a certain temperature gradient across it.

It has nothing to do with the velocity of the heat carriers themselves (phonons, or charged particles).

E.g. phonons always travel at the speed of sound, in any material.

▲MengerSponge 3 hours ago | parent | prev [-]

Slide 12. Pretty much yeah. https://indico.cern.ch/event/1541024/attachments/3055157/540...

You can kind of isolate the different vibrational modes and their corresponding energy transmission. "Phonons" are basically sound waves (the particle analogue), labeled in figure 2: https://www.nist.gov/system/files/documents/2019/07/12/dcs_2...

▲random3 3 hours ago | parent | prev [-]

Diamonds are crystals, like silicon Nothing wrong with liking shiny rocks, but they aren't that rare and we can generally produce them. Materials have properties. Understanding the properties generally gives us leverage to use them in our own benefit.

▲xnx 6 hours ago | parent | prev | next [-]

Asionometry video on the topic: Why Diamond Transistors Are So Hard (https://www.youtube.com/watch?v=NLmd5vL0zmk)

▲djoldman 3 hours ago | parent | prev | next [-]

Forget the transistor for now: that's many years/decades away.

Much more likely to actually get to market is diamond as the heat dissipating substrate.

▲Sath52 3 days ago | parent | prev | next [-]

Diamonds are incredibly useful,

And logical, now that we can produce them easily enough.

This, is one of many uses of the rocks.

▲rogerallen 3 hours ago | parent | prev | next [-]

Anyone else reminded of that old Crighton book, Congo?

▲T-A an hour ago | parent [-]

I was reminded of https://en.wikipedia.org/wiki/The_Diamond_Age

▲ 6 hours ago | parent | prev | next [-]
[deleted]
▲ginko 6 hours ago | parent | prev | next [-]

Why do people still think they need to mess with scrolling on their websites?

▲fhdkweig 4 hours ago | parent | next [-]

Normally, I am the first to complain about broken websites, but it looks fine for me on Firefox on a laptop. Scrolling works normal using up-down arrow keys and dragging on the side scrollbar. There is an unnecessary effect with the 3D diagram, but it doesn't interfere with the site. How are you viewing it?

▲peesem 3 hours ago | parent [-]

i think they mean the sort of "inertial" scrolling that the site imposes

▲fhdkweig 3 hours ago | parent [-]

hmm, I'm not seeing anything that can be described as "inertia". Not on chromium either. Both of these are on a laptop with dragging the side scrollbars and using the up/down arrows on the keyboard.

Is this something that is related to a touch screen? I'm not using a touch screen.

▲hatthew 2 hours ago | parent | next [-]

I'm on a non-touchscreen mac, on firefox with smooth scrolling turned off, and have LinearMouse installed. I tried both trackpad scrolling and mousewheel scrolling. The weird "smooth" scrolling of this website is very jarring to me, and makes it take significantly longer to scroll to where I want to, since the responsiveness went from ~instant to ~.5s and I keep on overshooting.

▲peesem 2 hours ago | parent | prev [-]

try using a mouse or trackpad, they only seem to intercept pointer input. i also don't get affected when dragging the scrollbar or using the arrow keys.

▲cwillu 5 hours ago | parent | prev [-]

I know; at least very little else breaks on the site if you just kill scripts in ublock origin.

▲amelius 3 hours ago | parent | prev | next [-]

But we need to move to photonics.

▲mitthrowaway2 2 hours ago | parent [-]

Maybe someone can find a way to make transparent diamond.

▲amelius 6 minutes ago | parent [-]

stuff that's always transparent doesn't modulate light very well

▲dude250711 6 hours ago | parent | prev | next [-]

And no, blog writers, it is not heralding "The Diamond Age".

▲notarobot123 2 hours ago | parent | next [-]

I don't know... LLMs, drones, culture wars, nostalgia for monarchical rule - we're only really missing the replicators and nano-engineering at this point.

▲Tepix 6 hours ago | parent | prev [-]

Recommended reading: https://en.wikipedia.org/wiki/The_Diamond_Age

▲db48x 5 hours ago | parent [-]

Way better to recommend reading the book instead of the Wikipedia page about the book.

▲ReptileMan 2 hours ago | parent | prev | next [-]

>single-crystal diamond wafer

Can you hear the sound of DeBeers' execs melting down? I intend to play it as a white noise while I sleep.

▲parineum 34 minutes ago | parent [-]

Their marketing works just as well to create the diamond market just as well as it does to make synthetic diamonds mean you don't really love her.

▲alberth 6 hours ago | parent | prev | next [-]

Isn't the power consumption needed to create pure/no-blemish lab diamonds so great, that this wouldn't be feasible to scale.

▲londons_explore 6 hours ago | parent | next [-]

Lab diamonds are used in huge quantities (ie. By the bucketful ) for making cutting tools like saws and drill bits.

I believe the main difficulty is making large and pure diamonds. Making small low purity diamonds is cheap and easy to scale.

▲jpitz 6 hours ago | parent | prev [-]

massive crushing pressure is not the only way to create diamond particles.

▲alberth 6 hours ago | parent [-]

do you mind explaining more

▲dmitrygr 6 hours ago | parent [-]

Chemical Vapor Deposition (CVD)

▲paaloeye 4 hours ago | parent | prev | next [-]

I'd be surprise if it gets even 1% of SI world dominance after 5 years

▲mitxela 6 hours ago | parent | prev | next [-]

I still don't know how to even make a silicon transistor.

▲genxy 5 hours ago | parent | next [-]

Make a Point Contact Transistor at home https://www.youtube.com/watch?v=vmotkjMSKnI

▲ForgotMyUUID 5 hours ago | parent [-]

Amazing video, seen it long ago. Spoiler : you will need two diodes to make one.

▲hvs 4 hours ago | parent [-]

Lucky me, I have exactly that many diodes.

▲mrguyorama 2 hours ago | parent | prev [-]

You ever play that really old Zachtronics game where you have to design circuits at the silicon level? (KOHCTPYKTOP: Engineer of the People)

Give me an inverter and single logic gate and I can by myself recreate computing. Give me a silicon wafer and dopants and I no longer know what I am doing. The structure is 3D and also somewhat abstract and I fail to be able to maintain the mental state to understand it.

I don't understand my mental barrier. I get the abstract theory and rough physical concepts, but somehow I can't pull features out of a micrograph like Ken Shirriff can.

▲ezrec 6 hours ago | parent | prev | next [-]

So... how long does the hydrogen gas layer last before it all seeps out?

▲pfdietz 6 hours ago | parent | next [-]

I believe these are hydrogen atoms covalently bonded to the carbon atoms on the surface of the diamond.

▲db48x 6 hours ago | parent | prev [-]

The hydrogen is not a gas.

▲poppafuze 5 hours ago | parent | prev | next [-]

protons wanna tunnel out.

▲phegler 6 hours ago | parent | prev [-]

Okay this is cool research

just one tiny tiny microscopic question...

why would someone use diamond wafer costing 1000x more than a silicon wafer??!

:)

▲TehCorwiz 6 hours ago | parent | next [-]

If I'm reading this correctly it's two or threefold. Faster switching times, which both increases max speed and reduces power consumption. Avoids flaws due to silicon doping, presently we add ions to silicon to get P or N type junctions and they've found a way to get P type junctions using "2D Hole Gas" which is basically a thin layer of voids inside the bulk diamond crystal after treatment and avoids a category of flaws that affect silicon yields. Third, and this is speculation, but diamond has a way higher thermal conductivity and lower thermal expansion coefficient, so it can likely withstand higher temps and conduct heat away faster.

▲ktm5j 6 hours ago | parent [-]

I think the better question is: what real world applications need these qualities enough to justify the cost? They mention cooling application, I don't buy that anyone is that interested in reducing hotspots in their chips even if it makes them last longer.

▲adrian_b 4 hours ago | parent | next [-]

For high-voltage applications (like power supplies) or high-power high-frequency applications (like radio transmitters) or high temperature applications (e.g. inside ovens or engines) silicon transistors are already in the process of being completely replaced by silicon carbide or gallium nitride transistors.

Despite the fact that those are much more expensive than silicon transistors, they are so much better that their use saves money in other parts of the system in which they are used.

Diamond transistors could be even better than SiC and GaN transistors, but there are many difficult technological problems that must be solved until being able to make commercial products.

The linked page reports some significant advances, which avoid a source of problems in the past, which were caused by the poor behavior of dopant impurities inside diamond crystals.

▲neerajsi 5 hours ago | parent | prev [-]

I had a family friend working on diamond semiconductors in the 90s. The application at that time was for sensors located in the hot section of a jet engine.

▲hansvm 6 hours ago | parent | prev | next [-]

> why?

>> 50x faster switching

It's hard to say which applications will benefit the most, but orders of magnitude improvement tend to enable qualitative shifts downstream.

Not to mention, 1000x is just the cost right now while the tech is new.

▲jbms 6 hours ago | parent | prev | next [-]

The higher the voltages it can handle, the faster it can switch efficiently, and the better the thermal performance, the wider its potential applications in power electronics.

▲luz666 5 hours ago | parent [-]

Hmm, power electronics is often so big, that might need a lot of diamond and could get pricy, who knows.

Very low power chips might be the main application, as there is already a huge market (laptops and phones).

Or maybe there will be a whole set of new rf chips, profiting from the clock speed.

▲zardo 5 hours ago | parent [-]

Power electronics isn't just grid scale equipment.

▲JoeAltmaier 4 hours ago | parent | prev | next [-]

Possibly on a par with the other exotic materials currently in use.

▲ReptileMan 2 hours ago | parent | prev [-]

The moment it becomes useful its cost will fall down to silicone prices really fast.

Right now you can buy 100g of diamonds for low teens in $ from China. Diamonds are produced in enormous quantities as abrasives. And if you do something on large scale you become better at it.

So far we haven't invested in big monocrystals because there was not much use for them aside from jewelry and probably other small niches. The moment some R&D makes something useful out of them - they will be Jevoned into oblivion.