Effect of different etching processes on edge breakdown suppression for planar InP/InGaAs avalanche photodiodes

With the progress of semiconductor processing technology, avalanche photodiodes (APDs) based on InP/InGaAs are used for high-speed optical receiver modules. Planar-type APDs give higher reliability than mesa-type APDs. However, planar-type APDs struggle with a problem of intense electric field at the junction curvature, which causes edge break-down phenomena at the junction periphery. In this paper, we focus our study on the effects of junction curvature for APDs performances by different etching processes followed by single diffusion to form p-n junction. The performance of each process is characterized by observing electric field profiles and carrier generation rates. From the results, it is understood that the optimum structure, which can minimize edge breakdown and improve the manufacturability, can be predicted. (C) 2002 Elsevier Science Ltd. All rights reserved.