AC Performance of Polysilicon Leaky-Mode MSM Photodetectors

Pulse response of polysilicon metal-semiconductor-metal (MSM) photodetectors fabricated in a standard CMOS processes is described, including demonstration of pulse full-width at half-max (FWHM) of 1.32 ns. Pulse FWHM as low as 0.81 ns has been measured, as have 10%–90% rise times of 0.39 ns. Measured detector performance is limited by laser diode modulation capabilities. An analytic expression for the time domain response in the presence of body and contact recombination is reported.