Metalorganic Vapor Phase Epitaxy of Thick and Uniform Single Crystal CdTe Epitaxial Layers on (211) Si Substrates for X-ray Imaging Detector Development

Metalorganic vapor phase epitaxy of uniform and thick single crystal CdTe on (211) Si substrates has been studied for x-ray imaging detector development. Periodic growth interruptions are introduced during thick CdTe layer growth in order to improve crystal quality. Thick single crystal CdTe layers with uniform material properties were obtained. When compared to continuously grown crystals, these growth interrupted crystals exhibited better uniformity in thickness and x-ray rocking curve values throughout the wafer. We further developed a (20 × 20) pixels x-ray imaging array using these crystals. The detector showed a low dark current per pixel, and the value was uniform among the pixels which are required criteria to improve the uniformity of detector response. These results demonstrate single crystals CdTe obtained in this study are suitable for x-ray imaging detector development.