Thermal annealing of metal-semiconductor contact for CZT detectors

CZT can be used for high-resolution X-ray and gamma-ray spectroscopy at room temperature. Previously the thermal annealing process has been studied to decrease the leakage current of the detector and obtain a stable detector performance. Because of its low work function, indium can be used as the metal contact for a CZT Schottky detector. The low temperature annealing effect on the In/CZT contact was studied in our work. A CZT Schottky detector with indium/CZT/gold structure was fabricated. The leakage current and the energy resolution of each detector were measured. The detector was annealed for 10 hours in vacuum, and for 2, 4, 8 hours in air. The leakage current and the energy resolution of the detector were measured after the annealing process and they were compared with the data before the annealing. It was found that the detector performance of the CZT Schottky detector was enhanced with the low temperature annealing process in air.