Effects of W and Mo crystalline texture on the angular distribution of sputtered atoms

Abstract

The effects of W and Mo surface crystalline texture on the angular distribution of sputtered atoms were investigated experimentally and by computer simulation. A small-sized planar DC magnetron was used to sputter the target by 200–300 eV Ar⁺ ions. The crystalline texture was formed under rolling of metal foils and during the preparation of metal bars and was controlled by X-ray diffraction analysis. For W and Mo foils, a strong anisotropy of the angular distribution was found. The character of angular distribution was different in the planes oriented perpendicularly and in parallel to the direction of rolling. In the first case, the angular distribution was peaked at the polar angle θ=0, while in the second case, the angular distribution, in addition to a maximum at θ=0, revealed a pronounced maximum at θ≈ 57° and ≈60° for Mo and W, respectively. For bars, no azimuthal anisotropy was observed, but the angular distribution was peaked at θ=37° (Mo) and θ=45° (W). This is in contrast to the case of non-textured Mo and W polycrystals, for which the angular distribution had a maximum at θ=0. Computer simulation technique in combination with the results of X-ray analysis was used to clarify the above experimental findings. It was demonstrated that the angular distribution of sputtered atoms can be successfully used for the determination of the crystalline texture of metals.

Keywords:

• magnetron
• sputtering
• angle distribution
• texture

Acknowledgement

One of the authors (VIS) thanks the Federal Agency of Science and Innovations for financial support (Contract No. 02.740.11.0389).