Low resistance transparent electrodes for large area flat display devices

The dynamic performance of large area, high-resolution flat panel displays is contingent upon the conductivity of the transparent electrode. Electropl ated copper and vacuum deposited aluminum bus bars attached to the sidewall s,of conventional SnO2 electrodes offer theoretical improvements in conduct ivity while maintaining the electrode transmittivity. In association with a reactive ion etching process for delineating the tin oxide, auto registrat ion methods for attaching copper by electroplating and aluminum by a resist lift off process are described, together with the achieved enhancement fac tors. A contact resistance between the aluminum and the tin oxide was found to significantly reduce the enhancement. The sidewall contact resistance l ies between 0.4 and 4.0 X 10(4) Omega mum(2), considerably lower than that previously reported for contacts to the tin oxide top surface. The enhancem ent factor for aluminum lies between two and three. The application of copp er did not suffer from a contact resistance and an order of magnitude enhan cement was obtained. We also report excellent adhesion, typically greater t han 200 kg/cm(2), of the metals to the tin oxide and identify the parametri c space for achieving this. (C) 2001 American Vacuum Society.