Long-wavelength infrared doping-spike PtSi detector

Abstract

By incorporating a 1-nm-thick p + doping spike at the PtSi/Si interface, we have successfully demonstrated extended cutoff wavelengths of PtSi Schottky infrared detectors in the long wavelength infrared (LWIR) regime for the first time. The extended cutoff wavelengths resulted from the combined effects of an increased electric field near the silicide/Si interface due to the p + doping spike and the Schottky image force. The p + doping spikes were grown by molecular beam epitaxy at 450 degree(s)C using elemental boron as the dopant source, with doping concentrations ranging from 5 X 10 19 to 2 X 10 20 cm -3 . Transmission electron microscopy indicated good crystalline quality of the doping spikes. The cutoff wavelengths were shown to increase with increasing doping concentrations of the p + spikes. Thermionic emission dark current characteristics were observed and photoresponse in the LWIR regime was demonstrated.