Passivation of copper with ammonia-free silicon nitride and application

Abstract

A layer for passivating copper, aluminum, or other refractory metal films using ammonia-free silicon nitride and structures produced by the method. A thin film transistor for use in a liquid crystal display, wherein the transistor has a gate, a source and a drain, and a gate insulator between the gate and an active silicon layer. The improvement is a layer of the ammonia-free silicon nitride deposited between the copper, aluminum, or other refractory metal gate and the gate insulator. Further, the gate is copper, aluminum, or another refractory metal and is deposited directly on the substrate. The layer of ammonia-free silicon nitride is also deposited on portions of the substrate adjacent the gate and the gate line extending therefrom. The structure provides stable and low-resistance electrical contact between copper, aluminum, or another refractory metal gate lines and a metallization layer of aluminum and/or molybdenum, includes using a conductive material, such as an indium tin oxide bridge. A metallization layer of the device is connected to the conductive material through a via hole extending to that portion of the conductive material which is not covered by the copper, aluminum, or another refractory metal.