Study on the structure characteristics of HgCdTe infrared detector using laser beam-induced current

The structure characteristics of typical n⁺-on-p HgCdTe infrared detector have been studied by laser beam-induced current (LBIC). The dependence of LBIC on laser wavelength, junction depth and localized leakage has been presented. The spreading length of minority carrier of p-type region (Lsp) is extracted by the exponential decay fitting of the curve of LBIC. It is found that the peak magnitude of LBIC and junction depth approximates to a linear relationship for practical values of device fabrication. The Lsp monotonously increases with junction depth. A notable shift of LBIC profile is observed when localized leakage exists. This provides a powerful explain for LBIC applying to characterize the structure and process uniformity of HgCdTe infrared detector.