Fabrication of CVD diamond photoconductive detectors

Abstract

We present an investigation on the fabrication of synthetic diamond based photon detectors. These devices are made by depositing small gap interdigitated contacts on polycrystalline diamond films grown by Microwave Plasma Enhanced Chemical Vapour Deposition. Gold interdigitated contacts were deposited on the typically rough surface of these films by using both wet etching and unconventional lift-off lithographic processes. These detectors were tested through X-ray irradiation in order to compare their potentialities in obtaining higher performance diamond photoconductive detectors. A better resolution was observed in samples obtained through the lift-off process. In particular for these samples the gap between electrodes could be kept very small and of the order of the grain size, giving higher response due the lower contribution of grain boundary effects.