PHOTOINDUCED CHANGES OF MECHANICAL-STRESS IN AMORPHOUS GE-AS-S(SE) FILM SI SUBSTRATE SYSTEMS/

Thin amorphous Ge-As-S(Se) films were deposited on Si substrates. Afte r deposition, a mechanical stress arises in the film due to the differ ence in lattice parameters. Photo-and thermo-structural changes were i nduced in the films by band-gap illumination or heat treatment. These structural changes cause the stress to change its value and/or sign. T hat is why the stress was used as a tool to investigate the photo-and thermo-induced changes. The investigation includes also a study of the compositional dependence of the stress in the chalcogenide film/Si su bstrate systems. Some infrared spectra have been measured in order to analyze the possible nature of the induced changes.