The Study for HgCdTe Far Infrared Detector Devices

• Main Authors: Hsin-Tien Huang, 黃鑫田
• Other Authors: Yan-Kuin Su
• Format: Others
• Language: en_US
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/47597742716092519653

碩士 === 國立成功大學 === 電機工程研究所 === 84 === A novel surface treatment method for obtaining high quality interface between passivation and HgCdTe is proposed. By stacking photo-enhanced-native-oxide and ZnS or CdTe films, we successfully passivated the HgCdTe. The high quality photo- enhanced-native-oxide is prepared by "direct photo chemical vapor deposition". By using this novel technique, we have fabricated the Au/ZnS(CdTe)/ photo-enhanced-native-oxide/HgCdTe structured metal- insulator-semiconductor (MIS) diodes and photoconductive (PC) detector devices. From capacitance-voltage (C-V) measurement, we found that the novel two-layer passivation structured HgCdTe MIS diode has a small flat band voltage, a low fixed oxide charge value and a small interface state density. For comparison, conventional Au/ZnS(CdTe)/HgCdTe structured MIS diodes and PC detectors were also fabricated. We found that diodes with the photo-enhanced-native-oxide layer have a much lower leakage current. From photo response measurement, lower noise, higher signal-to-noise ratio and larger specific detectivity (D*) values suggest that the novel two-layer passivation structured HgCdTe PC detector is much better than the conventional HgCdTe PC detector. These improvements are due to the good interface properties between the photo-enhanced-native-oxide and the HgCdTe substrate.