Turnover of texture in low rate sputter-deposited nanocrystalline molybdenum films

摘要

The crystallite size and orientation in molybdenum films prepared by magnetron sputtering at a low rate of typical 1 A/s and a pressure of 0.45 Pa was investigated by X-ray diffraction and texture analysis. The surface topography was studied using atomic force microscopy. Increasing the film thickness from 20 nm to 3 um m, the films show a turnover from a (110) fiber texture to a (211) mosaic-like texture.In the early state of growth (20 nm thickness) the development of dome-like structures whereas their size is weakly influenced. The effect of texture turnover is reduced by increasing the deposition rate by a factor of six, and it is absent for samples mounted above the center of the magnetron source. The effect of texture turnover is related to the bombardment of the films with high energetic argon neurals reswulting from backscattering at the target under oblique angle and causing resputtering. Due to the narrow angular distribution of the reflected argon. bombardment of the substrate plane is inhomogeneous and only significnat for regions. Close to the erosion zone of the magnetron.