Photodetector structures for standard CMOS imaging applications

In this investigation we show how a standard 0.5 mum twin-well CMOS process can be used for CMOS imaging. The process features a single-polysilicon layer, as well as three metal layers, and it is LOCOS based. We discuss various issues affecting photodetection tasks in CMOS imaging applications and present an extensive study of possible photodetector structures. Also, we propose a novel CMOS imaging pixel structure, which exceeds the standard CMOS 2-D imaging performance.