Modeling of InGaAs/AlGaAsSb APDs with high gain-bandwidth product

Modeling of InGaAs/AlGaAsSb avalanche photodiodes (APDs) is presented in this work. Based on a drift-diffusion theory, the APD dark- and photo-current and multiplication gain are simulated. The frequency response and bandwidth are also computed based on a derived formalism by following the carrier transit analyses. Modeling results of I-V curves, multiplication gain, breakdown voltage, excess noise factor, -3dB bandwidth and gain-bandwidth product are demonstrated. Some results are compared with the experimental report. The APD performance is further evaluated with respect to two of the key design factors, the multiplication and the absorption layer thickness, respectively.