Contact resistivity of metallized tin oxide surfaces

The dynamic performance of large-area, high-resolution flat panels is contingent upon the conductivity of the transparent electrodes. Aluminum bus bars vacuum deposited onto the sidewalls of conventional SnO2 electrodes provide a theoretical order-of-magnitude improvement in conductivity while maintaining the electrode transmittivity. A method for attaching aluminum bus bars by means of anisotropic reactive ion etching coupled with a resist lift-off process is described. Contact resistance between the aluminum and the tin oxide is found to reduce the enhancement factor to the range 2-3. The sidewall contact resistance lies between 0.4 x 10(4) Ohm mu m(2) and 4.0 x 10(4) mu m(2). This resistance was found to be considerably lower than that for contacts to the tin oxide top surface where an interlayer of gold was necessary to reduce the initial contact resistance from, typically, 3.5 x 10(7) to 5.0 X 10(4) Ohm mu m(2). (C) 2000 The Electrochemical Society. S0013-4651(99)03-130-4. All rights reserved.