Multiplication in SAGCM InP/InGaAs Avalanche Photodiodes

Planar separate absorption, grading, charge, and multiplication (SAGCM) InP/InGaAs APDs are ideal for studying the multiplication (photogain) versus bias voltage (M-V) characteristics. In this paper, the M-V characteristics in SAGCM InP/InGaAs APDs are investigated both experimentally and theoretically. The self-calibrated nature of M and the bias-voltage independent quantum efficiency make it possible to compare theory and experiment accurately in an InP-based APD for the first time. Using a physics-based model, the M-V characteristics for all the SAGCM APDs with different device parameters are calculated theoretically, and the calculations are in good agreement to the experimental results.