Silicon Technologies and Integrated Photodetectors

Abstract

In this chapter, the bipolar, CMOS, and BiCMOS process technologies are described. Photodetectors which are produced in these technologies without process modifications and their properties are introduced. Furthermore, the possible improvements of photodetectors resulting from small substrate and process modifications are discussed. CMOS is the economically most important technology. The section on integrated photodetectors in CMOS technology, therefore, is more comprehensive than the sections on photodetectors in bipolar and BiCMOS technologies. Within the CMOS section, the innovative integration of vertical PIN photodiodes will be highlighted, since they allow a considerable improvement of the speed of CMOS OEICs. Avalanche photodiodes and single-photon avalanche diodes (SPADs) are described. Furthermore, image sensors using charge-coupled-devices and active pixel image sensors will be described in some detail because of their economical importance. Within the BiCMOS section, the exploitation of double photodiodes will be mentioned as another innovation for high-speed OEICs and OPTO-ASICs in standard technology.