Process of growing polycrystalline silicon-germanium alloy having large silicon content

摘要

Polycrystalline silicon-germanium alloy is grown on a glass substrate through a chemical vapor deposition under the conditions where the substrate temperature ranges from 350 degrees to 450 degrees in centigrade, the ratio between gas flow rate of Si2H6 and the gas flow rate of GeF4 ranges from 20:0.9 to 40:0.9 and the dilution gas is selected from the group consisting of helium, argon, nitrogen and hydrogen, and the composition ratio of silicon of the polycrystalline silicon-germanium is equal to or greater than 80 percent so that the carrier mobility is drastically improved.