Analysis of thickness profiles of pulsed laser deposited metal films

Practically all theoretical approaches to pulsed laser deposition start on a condition which is extremely hard to realize in practice: that the target surface is smooth and plane. When using liquid (molten) targets, the probl em of surface deterioration upon repetitive ablation can completely be solv ed, allowing for fair comparison of experiment and theory. In this paper me asured thickness profiles of metal films deposited in vacuum from molten In , Sn, Bi and Sn-Bi alloy targets are compared with calculated distribution functions. The strictly symmetrical thickness profiles of tin and indium fi lms, derived from two-dimensional optical density maps and Rutherford backs cattering data are analysed in terms of Lorentzian-like functions, originat ing from the so-called shifted Maxwellian velocity distribution. The bismut h profiles show a characteristic deviation from this shape. (C) 1999 Elsevi er Science B.V. All rights reserved.