Dynamic behavior of photocarriers in a GaAs metal-semiconductor-metal photodetector with sub-half-micron electrode pattern

Simulation results of the temporal evolution of photocurrent in an interdigitated GaAs metal‐semiconductor‐metal photodetector are presented. The dependence of response time on the distance between fingers (0.1 and 0.25 μm) is investigated. The solutions of the time‐dependent Schrodinger equation and ensemble Monte Carlo calculations are employed. For a device with 0.1 μm finger spacing, the response time of an intrinsic detector is less than 2 ps, with hole current decay being the major limiting factor. The role of parasitics is shown to significantly increase the simulated response time.