Method for making silicon germanium alloy and electric device structures

摘要

A method for fabricating silicon-germanium alloy on a sapphire substrate of the present invention comprises the steps of passivating a surface of a sapphire substrate, maintaining a deposition temperature of about 900 degrees C., exposing the passivated surface to a flow of about 1 slm of about 2 percent silane in a hydrogen carrier and a flow of at least 200 sccm of about 10 percent germane in a hydrogen carrier to form a layer of single crystal silicon germanium alloy on the passivated surface of the sapphire substrate, and ramping the temperature down to about 650 degrees C. during the step of exposing the passivated surface to the germane gas.