The present invention relates to a process of making a zinc-oxide-based thin film semiconductor, for use in a transistor, comprising thin film deposition onto a substrate comprising providing a plurality of gaseous materials comprising first, second, and third gaseous materials, wherein the first gaseous material is a zinc-containing volatile material and the second gaseous material is reactive therewith such that when one of the first or second gaseous materials are on the surface of the substrate the other of the first or second gaseous materials will react to deposit a layer of material on the substrate, wherein the third gaseous material is inert and wherein a volatile indium-containing compound is introduced into the first reactive gaseous material or a supplemental gaseous material.