HIGH-TEMPERATURE SPUTTERED AMORPHOUS GAAS

Amorphous gallium arsenide films have been deposited on polycrystalline molybdenum and amorphous glass substrates heated at temperatures as high as 600 degrees C using rf sputtering. This has been achieved by operating at lower self-bias voltages when the substrate temperature is increased. The effect of the self-bias voltage on the crystallographic structure of the films is discussed in terms of the kinetic energy of the particles bombarding the growing film. Measurements of the chemical composition of the films using electron microprobe analysis show that films deposited on molybdenum substrates are stoichiometric at a substrate temperature of 400 degrees C.