Abstract
In this investigation we examine different pixel struc- tures and readout principles to be used in imagers fabricated in standard CMOS processes, for example, the 0.5 m and 0.35 m processes available at the Fraunhofer IMS. The targeted applications are high-speed near-infra-red (NIR) 3-D imaging based on time-of-flight (TOF) measurements. We discuss various issues ranging from charge-coupling possibilities to noise, spectral responsivity and fill-factor , and present an extensive study of pixel configurations based on inverse biased p-n junction and MOS-C based photodetectors. We also discuss the possibilities of using a novel CMOS imaging pixel for TOF imaging applications: the charge-injection photogate (CI-PG) which presents parametric time-compression amplification. Finally, we compare and discuss all the pixel configurations examined.