Two dimensional model for lateral photodiode

Abstract

The design of mixed signal systems on chip is nowadays challenging, especially those including active pixel sensors (APS) for imaging. To simulate such systems, it is necessary to use optoelectronic models of the behavior of the photodetectors. The most used photodetectors in CMOS technologies are vertical photodiodes, but for specific applications, lateral photodiodes are needed. Vertical photodiodes can be described by one dimensional models but in lateral photodiode, bidimensional effects appear. Therefore a physical two dimensional model of lateral photodiode has been developed. An electrical model was defined and physical parameters which take place in this model, were presented. The results were compared to an approximated one dimensional model and show that a two dimensional model is needed to simulate the light response of lateral photodiodes