Vapor-Phase Epitaxial Growth Of Thick Single Crystal Cdte On Si Substrate For X-Ray, Gamma Ray Spectroscopic Detector Development

We investigated MOVPE growth conditions to grow large-area and thick single crystal CdTe layers with uniform material properties directly on (211) Si substrates to develop nuclear radiation detectors. We found that group VI/II precursor flow-ratio as well as rapid thermal annealing performed by interrupting the growth at the initial stage has marked influence on the crystal quality. By using a VI/II precursor ratio of 3.0, and a 900 degrees C anneal performed in flowing hydrogen, we were able to achieve 1-sq inch sized thick single crystal CdTe that showed uniform material properties and high crystal quality throughout the wafer. We further demonstrated that the grown crystals were suitable for fabricating nuclear radiation detector. (C) 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)