The present invention provides a process for selectively etching molybdenum or titanium relative to a oxide semiconductor film, including providing a substrate comprising a layer of oxide semiconductor and a layer comprising molybdenum or titanium on the layer of oxide semiconductor; preparing the substrate by applying a photoresist layer over the layer comprising molybdenum or titanium, and then patterning and developing the photoresist layer to form an exposed portion of the layer comprising molybdenum or titanium; providing a composition comprising ammonia or ammonium hydroxide, a quaternary ammonium hydroxide and a peroxide; and applying the composition to the exposed portion for a time sufficient to etch and remove the exposed portion of the layer comprising molybdenum or titanium, wherein the etching selectively removes the molybdenum or titanium relative to the oxide semiconductor.