4 ms·

Copper is used for electrical traces, I take it. If technology allows for light (laser) based switching, could less metals be used in the construction?

kesor 8y ago
Copper allows creating a movement of electrons, which is what you usually call electricity. Any kind of light, while it allows transferring a signal, does need to have the signal transformed from electricity to light on one end, and from light to electricity on the other. Replacing a very long cable with a fiber that allows transferring the same signal using light is a way to save on copper. But in appliances themselves, having signals transformed to and from light is too expensive. So you won't find lots of light fibers inside of appliances.
- jeffreyrogers 8y ago
  I think the person you're replying to meant having the computing be done optically (switching by some optical rather than transistor means), so in theory if you could do that you wouldn't need any copper except to provide power to your optical computer. I doubt we'll ever get to the point where optical computing is more cost effective than what we currently have though.
- gazarsgo 8y ago
  Silicon photonics is changing this dynamic some, right?
pjc50 8y ago
Odd place to ask this question. As it happens, inside chips it's either (doped) silicon, aluminium (metal layers), or gold (bond wires). There's a reason why copper isn't used in chip manufacture; something to do with reacting with or diffusing into silicon dioxide.
- PhantomGremlin 8y ago
  There's a reason why copper isn't used in chip manufacture; something to do with reacting with or diffusing into silicon dioxide. Huh? A number of years ago when I was still doing chips, copper was quite popular. Wikipedia claims it still is[1]: copper-based processes continue to be the state of the art for the semiconductor industry today. As Wiki explains, the key is "dual-Damascene". They inlay copper into trenches. [1] https://en.wikipedia.org/wiki/Copper_interconnect https://en.wikipedia.org/wiki/Copper_interconnect
  - sephamorr 8y ago
    Expanding on above, Al-based BEOL interconnects were used until the process for making the more-difficult Cu interconnects matured around the turn of the millennium. Without precautions, Cu will diffuse into Si badly and generate tons of traps. TiN is a typical barrier material, but increasingly exotic materials are now being used in cutting edge nodes.

kesor 8y ago

Copper allows creating a movement of electrons, which is what you usually call electricity. Any kind of light, while it allows transferring a signal, does need to have the signal transformed from electricity to light on one end, and from light to electricity on the other. Replacing a very long cable with a fiber that allows transferring the same signal using light is a way to save on copper. But in appliances themselves, having signals transformed to and from light is too expensive. So you won't find lots of light fibers inside of appliances.

jeffreyrogers 8y ago
I think the person you're replying to meant having the computing be done optically (switching by some optical rather than transistor means), so in theory if you could do that you wouldn't need any copper except to provide power to your optical computer. I doubt we'll ever get to the point where optical computing is more cost effective than what we currently have though.
gazarsgo 8y ago
Silicon photonics is changing this dynamic some, right?

pjc50 8y ago

Odd place to ask this question. As it happens, inside chips it's either (doped) silicon, aluminium (metal layers), or gold (bond wires). There's a reason why copper isn't used in chip manufacture; something to do with reacting with or diffusing into silicon dioxide.

PhantomGremlin 8y ago
There's a reason why copper isn't used in chip manufacture; something to do with reacting with or diffusing into silicon dioxide. Huh? A number of years ago when I was still doing chips, copper was quite popular. Wikipedia claims it still is[1]: copper-based processes continue to be the state of the art for the semiconductor industry today. As Wiki explains, the key is "dual-Damascene". They inlay copper into trenches. [1] https://en.wikipedia.org/wiki/Copper_interconnect https://en.wikipedia.org/wiki/Copper_interconnect
- sephamorr 8y ago
  Expanding on above, Al-based BEOL interconnects were used until the process for making the more-difficult Cu interconnects matured around the turn of the millennium. Without precautions, Cu will diffuse into Si badly and generate tons of traps. TiN is a typical barrier material, but increasingly exotic materials are now being used in cutting edge nodes.