Doping-spike PtSi Schottky infrared detectors with extended cutoff wavelengths

A technique incorporating a p⁺ doping spike at the silicide/Si interface to reduce the effective Schottky barrier of the silicide infrared detectors and thus extend the cutoff wavelength has been developed. In contrast to previous approaches which relied on the tunneling effect, this approach utilizes a thinner doping spike (<2 nm) to take advantage of the strong Schottky image force near the silicide/Si interface and thus avoid the tunneling effect. The critical thickness, i.e., the maximum spike thickness without the tunneling effect has been determined and the extended cutoff wavelengths have been observed for the doping-spike PtSi Schottky infrared detectors. Thermionic-emission-limited and thermally assisted tunneling dark current characteristics were observed for detectors with spikes thinner and thicker than the critical thickness, respectively