MIS capacitor radiation sensor with giant internal signal amplification on a base of UHR epi silicon [photodetector]

The theoretical model of a new metal-insulator-semiconductor (MIS) radiation sensor, possessing a giant internal signal amplification, is proposed, to describe the experimentally obtained results. The sensor is fabricated on an ultra-high resistivity (UHR) epi layer (>10 k/spl Omega//spl middot/cm) on a heavily doped wafer. Theoretical modeling explains the giant value of the internal amplification of the signal that is determined as the ratio of peak values of readout currents and instantaneous photo current. With an integration time of about 1 sec, the amplification coefficient is of the order of 10/sup 4/ in the case of a 10-50 k/spl Omega/ external load, and it is of the order of 10/sup 6/ when the external load is smaller than 1 k/spl Omega/.