VLSI Technology and Dielectric Film Science

An important reason for the dominance of crystal silicon in electronics is the quality of its natural oxide. Silicon dioxide forms a glass film on the crystal, with an atomically abrupt interface between them. At the ordinary operating temperatures of the devices, it is mechanically stable, electrically insulating and chemically protective. Germanium and gallium arsenide, materials whose inherent electrical properties are superior to those of silicon, are at a disadvantage because of the inferior properties of their oxides: Germanium dioxide is water soluble, and the oxidation of gallium arsenide produces metallic precipitates.