C-GROWTH OF DC-SPUTTERED MO AND W THIN-FILMS

Molybdenum and tungsten thin films were deposited onto MgO(100) and am orphous substrates (silica, glass) by d.c.-sputtering in argon. Althou gh the gas used is neutral, the deposits realized for both metals with low deposition rates v(d) (< 6 nm min-1) presented an f.c.c. structur e. The occurrence of this structure was independent of the substrate n ature. A detailed study concerning molybdenum showed that for v(d) > 6 nm min-1, Mo systematically appeared in the bulk b.c.c. structure. It is proposed that the f.c.c. structure is stabilized by metalloid impu rities (C, N, O) present in the residual atmosphere. Special care was given to the orientation of the Mo and W f.c.c. layers on MgO(100), an d a (100) orientation was observed. It was found that these deposits e xhibit, under certain conditions, the same orientation on amorphous su bstrates, which is characteristic of a fiber texture of [100] axis. Th e crystallographic structure of the coatings was explored by X-ray, RH EED and THEED techniques. Surface composition was determined by AES.