Optimized Selective‐Area p‐Type Diffusion for the Back‐Illuminated Planar InGaAs/InP Avalanche Photodiodes by a Single Diffusion Process

Abstract

Herein, an alternative approach of selective‐area zinc diffusion technique by single rapid thermal diffusion (RTD) using a Zn3P2/Zn/SiO2 multilayer structure is proposed to realize p‐type doping in the InP cap so as to fabricate planar InGaAs/InP avalanche photodiodes (APDs). Through the optimization of selective‐area zinc diffusion in the InP cap, a low dark current, high responsivity, fast transient response, and high reliability near‐infrared back‐illuminated planar InGaAs/InP APD is obtained, which demonstrates a simple and efficient method for the development of high‐performance planar InGaAs/InP APD focal plane arrays.