A MOS transistor with a laser-patterned metal gate, and methods for its manufacture. The method generally includes forming a layer of metal-containing material on a dielectric film, wherein the dielectric film is on an electrically functional substrate comprising an inorganic semiconductor; laser patterning a metal gate from the metal-containing material layer; and forming source and drain terminals in the inorganic semiconductor in locations adjacent to the metal gate. The transistor generally includes an electrically functional substrate; a dielectric film on at least portions of the electrically functional substrate; a laser patterned metal gate on the dielectric film; and source and drain terminals comprising a doped inorganic semiconductor layer adjacent to the metal gate. The present invention advantageously provides MOS thin film transistors having reliable electrical characteristics quickly, efficiently, and/or at a low cost by eliminating one or more conventional photolithographic steps.