Manufacturable inverted metal-semiconductor-metal thin film III—V compound semiconductor detectors

Abstract

For the first time to our knowledge a single crystal, thin film III—V metal-semiconductor-metal (MSM) detector that has the Schottky metal contacts between the absorbing semiconductor material and the host substrate (glass and silicon) has been demonstrated. The MSM is formed by metallizing the smooth host substrate, placing the thin film epitaxial lift-off compound semiconductor material on top of the metal, and post annealing to form the Schottky barriers. This integration technology is important because there is no metal directly deposited onto the III—V compound semiconductor, and hence no contact definition and alignment step needs to be performed on the GaAs. The interdigitated contacts, which lie between the absorbing layer and the host substrate, eliminate finger shadowing, thereby potentially increasing the efficiency of the device. The extension of this work will ideally lead to inexpensive manufacturing processing for optoelectronic integrated circuits in which Si integrated circuitry will only need a final compound semiconductor device alignment, attach, and anneal step for optoelectronic detector integration.