The fabrication of p-Ge/n-Si photodetectors, compatible with back-end Si CMOS processing, by low temperature (< 400 °C) molecular beam epitaxy and electron-beam evaporation

Abstract

ABSTRACTWe report on the low temperature growth, by molecular beam epitaxy (375 °C) and electron-beam evaporation (300 °C), of p-Ge films on n-Si substrates for fabricating p-n junction photodetectors, aimed at the integration of opto-electronic components with back-end Si CMOS processing. Various surface hydrogen and hydrocarbon removal treatments were attempted to improve device properties. We invoke Ge diffusion and growth modes as a function of deposition temperature and rate to correlate structural analysis with the device performance.