Silicide/strained Si/sub 1-x/Ge/sub x/ Schottky-barrier infrared detectors

By employing a thin silicon sacrificial cap layer for silicide formation, the authors successfully demonstrated Pd/sub 2/Si/strained Si/sub 1-x/Ge/sub x/ Schottky-barrier infrared detectors with extended cutoff wavelengths. The sacrificial silicon eliminates the segregation effects and Fermi level pinning which occur if the metal reacts directly with Si/sub 1-x/Ge/sub x/ alloy. The Schottky barrier height of the silicide/strained Si/sub 1-x/Ge/sub x/ detector decreases with increasing Ge fraction, allowing for tuning of the detector's cutoff wavelength. The cutoff wavelength was extended beyond 8 mu m in PtSi/Si/sub 0.85/Ge/sub 0.15/ detectors. It is shown that high quantum efficiency and near-ideal dark current can be obtained from these detectors.>