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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

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 9y 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.