8 ms·

From what i have read, with my limited understanding of chipmaking, it seems that UO2(Uranium dioxide) makes a great heat and radiation resistant semiconductor

From what i have read, with my limited understanding of chipmaking, it seems that UO2(Uranium dioxide) makes a great heat and radiation resistant semiconductor with better properties than silicon or germanium[1]. So how come we arent using that or exploring other materials for pushing the limits of computational power? [1]: https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.522.5718&rep=rep1&type=pdf https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.52...

userbinator 6y ago
The mere mention of uranium is going to make the paranoid scared, and nuclear regulatory agencies raise much concern. Even "depleted" uranium is somewhat radioactive, and it's a toxic heavy metal.
- ClumsyPilot 6y ago
  A modern pc is toxic, it's not like you could survive stuffing an iPad in a blender and eating it. Thats why e-waste is causing so many problems.
  - a1369209993 6y ago
    > it's not like you could survive stuffing an iPad in a blender and eating it To be fair, I think the sharp chunks of metal and plastic would kill you before the heavy-metal poisoning could.
  - kens 6y ago
    I doubt an iPad would kill you. One guy ate 7 TV sets, a computer, bicycles, and an entire Cessna 150 aircraft. https://en.wikipedia.org/wiki/Michel_Lotito https://en.wikipedia.org/wiki/Michel_Lotito
    - totalZero 6y ago
      The Frenchman ate an airplane and died of natural causes at the age of 57. Now there's a sentence that I never thought I'd write.
- baybal2 6y ago
  Lots of stuff far worse than uranium is used in semiconductor manufacturing.
the8472 6y ago
U238 is an alpha emitter. You'd probably get way more bitflips than non-radioactive semiconductors experience.
philipkglass 6y ago
Probably a few factors: - Difficulty growing high quality crystals - All the process chemistry for building devices would be different - Toxicity/radioactivity The third one is IMO the least important. There are a lot of semiconductor materials that theoretically have properties comparable to or better than silicon for solar cells (as this paper suggests). But having a theoretically good band gap doesn't matter if the actual material as grown is full of deleterious defects. We're really good at growing near-perfect silicon crystals. We're not so good at growing perfect crystals of iron (II) sulfide, uranium dioxide, etc. Even if that could be solved, re-developing all the chemistry and tooling for fabricating dense logic/memory devices based on uranium dioxide instead of silicon would require an extraordinary investment of money and time. It could be comparable to or even more expensive than the transition to extreme ultraviolet lithography.
- omgJustTest 6y ago
  Chemical scarcity should be in your list, and it is the reason silicon will remain for years to come, at least in electric domains.
  - retrac 6y ago
    Yep. I tried to ballpark the amount of polysilicon used to actually make ICs. Somewhere between 100,000 and 10 million tonnes a year, I figure. Those little dies are only 100 mg or so but we print them by the billions. Whether the real number is more to the high or low end of that, it's hopeless. As Wikipedia says "About 118 tonnes of germanium was produced in 2011 worldwide."
    - fuzzfactor 6y ago
      It can require very pure materials to make conductors and semiconductors or they won't act right. And it can take kilos of 99 percent pure raw material to end up with a few grams of 99.999 or better. Silicon was already available in rail cars having 99+ percent purity for steelmaking.

userbinator 6y ago

The mere mention of uranium is going to make the paranoid scared, and nuclear regulatory agencies raise much concern. Even "depleted" uranium is somewhat radioactive, and it's a toxic heavy metal.

ClumsyPilot 6y ago
A modern pc is toxic, it's not like you could survive stuffing an iPad in a blender and eating it. Thats why e-waste is causing so many problems.
- a1369209993 6y ago
  > it's not like you could survive stuffing an iPad in a blender and eating it To be fair, I think the sharp chunks of metal and plastic would kill you before the heavy-metal poisoning could.
- kens 6y ago
  I doubt an iPad would kill you. One guy ate 7 TV sets, a computer, bicycles, and an entire Cessna 150 aircraft. https://en.wikipedia.org/wiki/Michel_Lotito https://en.wikipedia.org/wiki/Michel_Lotito
  - totalZero 6y ago
    The Frenchman ate an airplane and died of natural causes at the age of 57. Now there's a sentence that I never thought I'd write.
baybal2 6y ago
Lots of stuff far worse than uranium is used in semiconductor manufacturing.

the8472 6y ago

U238 is an alpha emitter. You'd probably get way more bitflips than non-radioactive semiconductors experience.

philipkglass 6y ago

Probably a few factors: - Difficulty growing high quality crystals - All the process chemistry for building devices would be different - Toxicity/radioactivity The third one is IMO the least important. There are a lot of semiconductor materials that theoretically have properties comparable to or better than silicon for solar cells (as this paper suggests). But having a theoretically good band gap doesn't matter if the actual material as grown is full of deleterious defects. We're really good at growing near-perfect silicon crystals. We're not so good at growing perfect crystals of iron (II) sulfide, uranium dioxide, etc. Even if that could be solved, re-developing all the chemistry and tooling for fabricating dense logic/memory devices based on uranium dioxide instead of silicon would require an extraordinary investment of money and time. It could be comparable to or even more expensive than the transition to extreme ultraviolet lithography.

omgJustTest 6y ago
Chemical scarcity should be in your list, and it is the reason silicon will remain for years to come, at least in electric domains.
- retrac 6y ago
  Yep. I tried to ballpark the amount of polysilicon used to actually make ICs. Somewhere between 100,000 and 10 million tonnes a year, I figure. Those little dies are only 100 mg or so but we print them by the billions. Whether the real number is more to the high or low end of that, it's hopeless. As Wikipedia says "About 118 tonnes of germanium was produced in 2011 worldwide."
  - fuzzfactor 6y ago
    It can require very pure materials to make conductors and semiconductors or they won't act right. And it can take kilos of 99 percent pure raw material to end up with a few grams of 99.999 or better. Silicon was already available in rail cars having 99+ percent purity for steelmaking.