Image Sensor Technology

Abstract

Single photon imaging is an extension of solid state imaging, making use of devices that benefit from the outstanding electro-optical properties of silicon and which have the potential, like CCD and CIS devices before, to benefit from the integration made possible with silicon process technology. This chapter provides an introduction to the functionality of integrated image sensors. It presents the typical process flow and a discussion of where the technology used to build CMOS logic and mixed signal parts is useful to provide the special performance and unique features expected in imaging. As a conclusion, process enhancements including special process modules and design rules for high-performance image sensors are discussed. This chapter also addresses the question to which degree single photon imaging devices can be an extension of the CIS model to achieve mass commercialization. The goal is to build valuable imaging products with an existing fabrication tool set, derived from a conventional CMOS process with some process enhancements using existing tools. This implies that the commercially interesting pixel array design can be achieved using special design rules, and that the process enhancements will support the operating voltages and clock rates required for single photon detection.