STRUCTURAL CHARACTERIZATION OF UNHYDROGENATED AMORPHOUS GAAS

Films of unhydrogenated amorphous gallium arsenide have been deposited by reactive rf sputtering. Substrate temperature or deposition power or argon pressure were allowed to change, in different deposition runs, to obtain groups of specimens deposited with only one variable parameter. Transmission electron microscopy (TEM) and transmission high energy electron diffraction (THEED) measurements have been made in order to determine the structure and the morphology of the films. The THEED patterns show that the structure has a short range order and a weak dependence on deposition conditions. The TEM micrographs show that the morphology of the films is strongly affected by the deposition conditions