FILM STRESS IN Pd//2Si LAYERS OF VARYING THICKNESS.

Little is known about the development of film stresses in very thin films (thicknesses of the order of a few hundred Angstroms or less). As interest intensifies in the technological application of ever smaller quantities of materials, the behavior of very thin films will undergo increasing scrutiny. In this study, the film stresses in evaporated Pd films and Pd//2Si films formed by reaction with the Si substrates at 250 degree C were measured for thicknesses ranging from 7 to 107 nm. Stresses were calculated from the substrate radii of curvature determined by X-ray diffraction topography techniques (Lang and double crystal) and Stoney's equation. Because film continuity cannot be taken for granted at low coverage, the films were examined by electron microscopy in an attempt to correlate their morphology with the observed stresses.