Abstract: In accordance with the invention a metal film structure having tapered sidewalls is made by the steps of applying a first layer of metal on a substrate, applying a second layer of a different material over the first layer, forming a pattern of resist on the second layer and etching the first and second layers in an etchant. The material of the second layer is chosen to interact with the metal of the first layer to increase the lateral etch rate of the second layer, thereby producing a metal film structure having tapered sidewalls. In preferred embodiments, the first layer is Cr, the material of the second layer is Mo, and the etchant is ceric ammonium nitrate. The preferred application of the method is to make conductive thin film lines for thin film transistor arrays used in active matrix liquid crystal displays.