“Silicon life”, referring to organisms based on a silicon biochemistry, has been suggested as an alternative to carbon life since silicon has chemical properties similar to carbon at high temperatures. Science fiction has speculated about silicon-based life on planets with high temperatures and pressures, although biologists are skeptical because there would have to be a highly effective bipolar solvent to fill the role of water there. It appears none exists.

As far as I know, only a few organisms on earth (mostly marine microbes) use silicon compounds as a structural material. Some diatoms construct their shells out of glass, silicon dioxide (SiO2) or silica. You will note the carbon analog of silica (CO2) is a gas in earth’s surface temperature regime.

Computers and robots may have elemental silicon or carbon components, but they are not life at all. They are artifacts which must be constructed by organic beings or other robots. It is not clear how they could evolve in a natural environment from simpler, preorganic components.