CRYSTAL GROWTH AND ORIENTATION IN VACUUM-CONDENSED METAL DEPOSITS - A SYSTEMATIC CORRELATION WITH RESIDUAL PRESSURE, RATE OF DEPOSITION AND THICKNESS

Extensive electron diffraction studies have been made of the surface structure of tin films condensed in vacuum on to glass substrates initially at room temperature. Rates of deposition were 0-150 Å s-1, film thicknesses up to 5000 Å and residual air pressures 10-8- 10-3 torr. The preferred orientation of the tin crystals depends systematically on the air pressure, as well as on the film thickness and rate of deposition. At 10-7 torr or less, at up to 70 Å s -1, the tin was very strongly oriented with {100} planes parallel to the substrate, but at 10-6-10-5 torr this was mixed with a less strong {001} orientation, and at higher pressures {001}, {301} or {110} orientation occurred in particular regions of the variables. These orientations other than {100} evidently arose because the corresponding plane faces were developed on the growing crystals, depending on the amount of adsorption of the residual gas on the crystal surface.