CuGaSe2 thin films were produced by a rapid thermal processing step from evaporated stacked elemental layers of the pure elements. The CuGaSe2 films were analyzed with respect to composition, defect levels and crystallographic phases. To gain insight into the variation of these attributes at different depth, the layers were successively etched in bromine methanol and characterized afterwards. The aim of this work is to investigate the properties of RTP reacted films in general and to disclose influences of the precursor structure on the reacted material.