Efficient p-InP(Rh-H alloy) and p-InP(Re-H alloy) Hydrogen Evolving Photocathodes

Abstract

The process of coating a rotating silicon substrate with fluid polymers to obtain thin dielectric films has been investigated. This study has been restricted to fluids and processing commonly associated with the semiconductor industry. Fluids with viscosities of 28, 43, 1100, and 2040 cp have been used to determine the effects of fluid volume, initial spin speed, final spin speed, spin acceleration, and final spin time on the final film thickness and thickness uniformity. Data are presented which show the quantitative dependence of thickness and thickness uniformity on these parameters and the optimum parameter values which yield reproducible, uniform films. A sophisticated film thickness optical measurement technique is described along with a bootstrap method for determining the Cauchy coefficients of the film. We present an empirical expression which describes the film thickness as a function of the measured parameters. High speed photography was used to understand the dynamics of the spin coating process.