Combinatorial approach to morphology studies of epitaxial thin films

Abstract

Described is the application of a combinatorial physical vapor deposition (CPVD) method for studying the growth dynamics of epitaxial films. The CPVD method takes advantage of the angle-dependent evaporation rate from a point source to produce thin film libraries whose deposition rate changes continuously for a factor of 50 across a 70-mm long-substrate. The link between the deposition rate and the resulting thin film morphology was made by spatially correlated absorption and atomic force microscopy measurements. It is shown that the growth of tryphenyldiamine derivate on a silica surface proceeds by three-dimensional growth of isolated islands which, at some critical coverage, coalesce to form uniform amorphous film. While the critical coverage of such films depends on the deposition rate in the 0.015-0.4 nm/s region, the particle size distribution function does not.