Pentacopper silicide is a binary compound of silicon with copper.

It forms upon heating mixtures of copper and silicon.

Copper silicide thin film is used for passivation of copper interconnects, where it serves to suppress diffusion and electromigration and serves as a diffusion barrier.

[3][better source needed] Copper silicides are invoked in the Direct process, the industrial route to organosilicon compounds.

In this process, copper, in the form of its silicide, catalyses the addition of methyl chloride to silicon.