STUDY OF A BACKGATED METAL-SEMICONDUCTOR-METAL PHOTODETECTOR

In this letter we outline our results on a new type of high-speed phot odetector [E. Gregor et al., Appl. Phys. Lett. 65, 2223 (1994)]. The d evice is based on the hybridization of a metal-semiconductor-metal pho todetector and a p-i-n photodiode. The advantage of the device, which operates in the transit-time Limited regime, is that it removes the ho le current from the high-speed circuit through a third contact, and he nce, increases the response speed of the device. In contrast to the pr eviously published work [E. Gregor ct al., Appl. Phys. Lett. 65, 2223 (1994)] we have used an excitation pulse that is much faster than the device response in order to fully investigate the effect of the third contact. We observe significantly more effect on the response once the third contact is connected with a subsequent increase of device respo nse speed with increasing application of bias to this third contact. ( C) 1996 American Institute of Physics.