Structure and Annealing Behavior of Metal Films Deposited on Substrates near 80 °K. II. Gold Films on Glass

Abstract

An in situ x-ray investigation of gold films has been carried out. Films were deposited on glass near 80 °K in high vacuum. Measurements were made on the as-deposited films as well as after annealing at temperatures up to 370 °C. In the as-deposited films the following results were obtained: (1) The lattice parameter perpendicular to the film surface was a few tenths of a percent less than the bulk value. (2) The films contained large numbers of intrinsic stacking faults and twins. (3) Nonuniform strains of the order of a few percent were also present. (4) The true crystallite sizes were estimated to be between several hundred and one thousand angstroms, where the estimate depended mainly on how the twin fault density was measured. (5) These films were (111) oriented with the strongest texture occurring in the thinnest film. When the films were annealed, changes in integrated x-ray intensity and line shapes were observed to occur near −15 °C. After room-temperature anneals, the imperfection densities had annealed out to such an extent that no contributions to line broadening and peak shifts could be detected. Grain growth occurred also upon annealing the films. A tendency towards the formation of a (100) texture was observed. The relative amount of growth occurring in the various (hkl) oriented crystallites was explained qualitatively in terms of surface and strain energies, the latter resulting from the difference in thermal expansion coefficients between film and substrate.