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We're incredibly lucky that copper and silicon are so (relatively) easy to work with. Imagine if even basic electrical systems needed wires made of rhodium and

We're incredibly lucky that copper and silicon are so (relatively) easy to work with. Imagine if even basic electrical systems needed wires made of rhodium and semiconductors only worked at cryogenic temperatures. We'd never have gotten over the "technological activation energy" in the 1800s.

WJW 3y ago
For sure. When you look at a used car lot or a smartphone for a few hundred dollars, it is easy to forget that they are the product of a system involving (at least!) hundreds of thousands of people working together in a system that has been studied and optimized for decades. Maybe we'll eventually reach consumer grade graphene processors, but if we do it will probably take decades for the technology to advance through the technology readiness levels.
amelius 3y ago
I think about this sometimes. Also, what if Pythagoras' formula didn't exist or was some king of hypothesis or a very long formula: where would technology be?
lizknope 3y ago
Copper was not always easy to work with in semiconductor chips. When I started in the industry in the 1990's all the wiring was aluminum. Articles about copper for wiring were research projects and which company would be the first to get it to mass production. IBM was the first in 1997 and then others followed. https://en.wikipedia.org/wiki/Copper_interconnects https://en.wikipedia.org/wiki/Copper_interconnects That's how technology is. Things start out hard and with a lot of work and time we invent new methods. Aluminum was once worth more than gold. Then we invented new processes of extraction and refinement. https://clintonaluminum.com/aluminum-was-once-worth-more-than-gold-and-silver/ https://clintonaluminum.com/aluminum-was-once-worth-more-tha...
- magicalhippo 3y ago
  Asianometry recently released a nice video[1] going into the transition to copper interconnects. [1]: https://www.youtube.com/watch?v=XHrQ-Pmvwao https://www.youtube.com/watch?v=XHrQ-Pmvwao
- gosub100 3y ago
  Can I ask an un-related question? In a CPU with thousands of pins, how come they use N pins for ground, N pins for VCC, when it seems simpler to have continuous bar-shaped contacts? Then pins would only be necessary for signals that actually changed. I see this in computer power supplies as well, they use N separate wires to carry V+ and N more for GND, but if you need more current why not use a thicker wire and only have 2?
  - dmoy 3y ago
    > In a CPU with thousands of pins, how come they use N pins for ground, N pins for VCC, when it seems simpler to have continuous bar-shaped contacts? I can't speak to cpus with thousands of pins, but with significantly smaller chips that often have N>1 vcc or ground, it's typically due to layout convenience. The multiple vcc may be on e.g. opposite sides of the chip, and that makes it easier to route a pure vcc signal to a spot that needs it. It's easier to route outside the chip than inside the chip, because there's more space.
    - mrWiz 3y ago
      Additionally, there's also a benefit to standardization. Adding different pin styles makes the part harder to design and manufacture.
  - Thetawaves 3y ago
    This improves the impedance of high speed signal transmission - at high speeds the currents want to flow through the ground path as close to the signal path as is possible. Said another way - designers work to reduce the total area inside the electric circuit to support high switching speeds. The additional power pins in high pin count chips serve to reduce the distance between high speed signal paths and their return ground paths. This is actually true for both ground and vcc, but is easier to visualize when working with signals and their grounds.
  - undersuit 3y ago
    > if you need more current why not use a thicker wire and only have 2 How do you route that current in one pin to the two locations the two pins handled? You've just moved the point where the split happens from on the motherboard to on the chip package.
- adhesive_wombat 3y ago
  Perhaps not trivial in chip interconnects, but it's fairly abundant and a rather workable material in general (hence the bronze age). Faraday probably wouldn't have gotten very far if copper was a gas at room temperature or only occured in trace amounts and there were no other ductile, solid conductive materials on Earth.
  - lazide 3y ago
    Sure, though carbon and salt water is also reasonably conductive. Power distribution via hydraulics instead?
- undersuit 3y ago
  I think they're talking about copper electrical wiring not semiconductor use. If we couldn't use simple copper to bootstrap our energy intensive aluminum industry in the 1800s we might be using rhodium.
m463 3y ago
I think what happened is we found something rare with interesting properties, then we sort of cost-optimized with other materials until we found something cheaper with similar properties. I think the germanium point contact transistor was sold, but eventually got us via practical methods to the silicon chips we have now. We have had more expensive exotic materials like gallium arsenide. So I think his comment in the article will happen: “Now that we know what structural and electronic properties are needed to achieve the new transport regime discovered in this work, there is good likelihood that we will find earth-abundant alternatives to this rhenium-based material that also show impressive transport properties,” Delor says.

WJW 3y ago

For sure. When you look at a used car lot or a smartphone for a few hundred dollars, it is easy to forget that they are the product of a system involving (at least!) hundreds of thousands of people working together in a system that has been studied and optimized for decades. Maybe we'll eventually reach consumer grade graphene processors, but if we do it will probably take decades for the technology to advance through the technology readiness levels.

amelius 3y ago

I think about this sometimes. Also, what if Pythagoras' formula didn't exist or was some king of hypothesis or a very long formula: where would technology be?

lizknope 3y ago

Copper was not always easy to work with in semiconductor chips. When I started in the industry in the 1990's all the wiring was aluminum. Articles about copper for wiring were research projects and which company would be the first to get it to mass production. IBM was the first in 1997 and then others followed. https://en.wikipedia.org/wiki/Copper_interconnects https://en.wikipedia.org/wiki/Copper_interconnects That's how technology is. Things start out hard and with a lot of work and time we invent new methods. Aluminum was once worth more than gold. Then we invented new processes of extraction and refinement. https://clintonaluminum.com/aluminum-was-once-worth-more-than-gold-and-silver/ https://clintonaluminum.com/aluminum-was-once-worth-more-tha...

magicalhippo 3y ago
Asianometry recently released a nice video[1] going into the transition to copper interconnects. [1]: https://www.youtube.com/watch?v=XHrQ-Pmvwao https://www.youtube.com/watch?v=XHrQ-Pmvwao
gosub100 3y ago
Can I ask an un-related question? In a CPU with thousands of pins, how come they use N pins for ground, N pins for VCC, when it seems simpler to have continuous bar-shaped contacts? Then pins would only be necessary for signals that actually changed. I see this in computer power supplies as well, they use N separate wires to carry V+ and N more for GND, but if you need more current why not use a thicker wire and only have 2?
- dmoy 3y ago
  > In a CPU with thousands of pins, how come they use N pins for ground, N pins for VCC, when it seems simpler to have continuous bar-shaped contacts? I can't speak to cpus with thousands of pins, but with significantly smaller chips that often have N>1 vcc or ground, it's typically due to layout convenience. The multiple vcc may be on e.g. opposite sides of the chip, and that makes it easier to route a pure vcc signal to a spot that needs it. It's easier to route outside the chip than inside the chip, because there's more space.
  - mrWiz 3y ago
    Additionally, there's also a benefit to standardization. Adding different pin styles makes the part harder to design and manufacture.
- Thetawaves 3y ago
  This improves the impedance of high speed signal transmission - at high speeds the currents want to flow through the ground path as close to the signal path as is possible. Said another way - designers work to reduce the total area inside the electric circuit to support high switching speeds. The additional power pins in high pin count chips serve to reduce the distance between high speed signal paths and their return ground paths. This is actually true for both ground and vcc, but is easier to visualize when working with signals and their grounds.
- undersuit 3y ago
  > if you need more current why not use a thicker wire and only have 2 How do you route that current in one pin to the two locations the two pins handled? You've just moved the point where the split happens from on the motherboard to on the chip package.
adhesive_wombat 3y ago
Perhaps not trivial in chip interconnects, but it's fairly abundant and a rather workable material in general (hence the bronze age). Faraday probably wouldn't have gotten very far if copper was a gas at room temperature or only occured in trace amounts and there were no other ductile, solid conductive materials on Earth.
- lazide 3y ago
  Sure, though carbon and salt water is also reasonably conductive. Power distribution via hydraulics instead?
undersuit 3y ago
I think they're talking about copper electrical wiring not semiconductor use. If we couldn't use simple copper to bootstrap our energy intensive aluminum industry in the 1800s we might be using rhodium.

m463 3y ago

I think what happened is we found something rare with interesting properties, then we sort of cost-optimized with other materials until we found something cheaper with similar properties. I think the germanium point contact transistor was sold, but eventually got us via practical methods to the silicon chips we have now. We have had more expensive exotic materials like gallium arsenide. So I think his comment in the article will happen: “Now that we know what structural and electronic properties are needed to achieve the new transport regime discovered in this work, there is good likelihood that we will find earth-abundant alternatives to this rhenium-based material that also show impressive transport properties,” Delor says.