Monolithic System Integration of Optical Devices, Photodetectors and Analog Transimpedance CMOS Amplifiers

The monolithic system integration of optical components, photodetectors and analog transimpedance CMOS amplifiers is shown. On the basis of a submicron CMOS process an advanced SWAMI LOCOS technique is applied. Different optical devices like waveguides, beam splitters, interferometers and mirrors have been integrated. The optical system consists of a SiON layer deposited on 2μm field oxide. The waveguides are made of structured SiO
₂
layers on top of the SiON layer. Leaky wave or butt coupled photodiodes and phototransistors are used as light detectors. The photocurrents are amplified by low noise CMOS transimpedance amplifiers with high sensitivity. They were designed for a large dynamic range of photocurrents, short recovery times, low noise and optimized reliability in fabrication.