Study of 3D TCAD Simulation on CMOS-Compatible Avalanche Photodetectors

Abstract

Importance of avalanche photodetectors (APDs) is growing more and more in many fields, from light detection and ranging (LiDAR) and time of flight (ToF) to biomedical imaging. For this reason, APD-based sensors in standard complementary metal-oxide-semiconductor (CMOS) technology have been receiving considerable attention from both scientific and industrial communities since they can provide high-accuracy range and low-level light detection capabilities in a cost-effective manner. In order to understand and make optimal CMOS-compatible APDs (CMOS-APDs), precise device simulations need to be preceded [1]. However, most of the researches have focused on 2-dimensional (2D) simulations, which may not match the real CMOS-APDs. In this paper, we present various simulation analyses of CMOS-APDs in 3-dimensions (3D) using Synopsys Sentaurus technology computer-aided design (TCAD). With the aid of TCAD simulation, investigation of E-field profiles of different CMOS-APD structures is performed. In addition, comparisons of I-V characteristics, photodetection frequency responses and gain characteristics with and without incident light of various CMOS-APD structures are analyzed. In addition, by comparing different CMOS-APD structures, the potential sources that influence characteristics of CMOS-APDs are identified.