Two-dimensional computer simulation of the breakdown characteristics of a multi-element avalanche photodiode array

A two-dimensional computer simulation of the breakdown characteristics of a silicon multi-element avalanche photodiode array has been carried out. The effect of the interaction of the depletion layers of two adjacent avalanche photo diode (APD) elements on the breakdown voltage of the multi-element array has been modeled. The influence of the various physical parameters of the device on its breakdown voltage is investigated. Five different device structures are considered. Design guidelines for realizing true bulk breakdown in the device are presented. With the aid of these two-dimensional computer simulation results, the effect of scaling down the device dimensions, in an effort to increase the packing density of the device, on its breakdown voltage is also outlined.