Doping-Induced Bandwidth Enhancement in Metal-Semiconductor-Metal Photodetectors

We demonstrate a novel technique for enhancing metal-semiconductor-metal photodetector bandwidths without reducing responsivity. We have observed bandwidth increases of up to 10 GHz from control to enhanced photodetectors which corresponds to about 70% enhancement. This technique involves modifying the internal electric field structure, by introducing a buried n-type doped layer that is completely depleted, to reduce the relatively long hole transit time. © 1991 IEEE