Bottom collection of photodiode-based CMOS APS

The market for solid-state image sensors has been experiencing an explosive growth in recent years resulting in CMOS sensors rapidly becoming one of the emerging sectors with more projection potential in the semiconductors industry. A CMOS active pixel sensor (APS) with a reverse biased p-n junction photodiode constitutes the structure of more widespread use, and it has been made a viable alternative to CCDs with the advent of deep submicron CMOS technologies and microlenses. Peripheral area of the junction depletion region plays an important role on collecting photocarriers in the vicinity of photodiode limits. In this paper, the peripheral photoresponse of CMOS APS of different dimensions in a deep submicron 0.18iquestm process is studied, paying special attention to the bottom collection.

keywords: CMOS image sensors, CMOS technology, Electronics industry, Explosives, Image sensors, Lenses, Microoptics, P-n junctions, Photodiodes, Solid state circuits