Analysis of a GaAs metal-semiconductor-metal (MSM) photodetector with 0.1- mu m finger spacing

The temporal response of a GaAs metal-semiconductor-metal (MSM) photodetector with a finger spacing of 0.1 mu m is discussed. The intrinsic detector has a minor effect (25% increase) on the full width at half-maximum (FWHM) of the temporal response of the device and its parasitic circuit elements. The analysis indicates that a long time constant due to the decay of holes is solely responsible for this increase. The smallest FWHM for this detector is estimated to be less than 2.5 ps.<
>