| Summary: | 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.
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