220-MHz monolithically integrated optical sensor with large-area integrated PIN photodiode

We propose a PIN photodiode integrated in a BiCMOS process which combines a quantum efficiency of nearly 100% for red light, fast response times, and a low junction capacitance. Bandwidths of 720 MHz at 660 nm and 683 MHz at 850 nm are achieved for this PIN photodiode. It allows the design of fast optoelectronic integrated circuits for many advanced applications in optical sensing, optical storage systems, and optical data transmission for optical wavelengths ranging at least from 660 to 850 nm. Because of the low photodiode capacitance of 0.01 fF//spl mu/m/sup 2/, it is possible to achieve high bandwidths, even with large photodetector areas. The proposed optical receiver employing a PIN photodiode with a diameter of 500 /spl mu/m and a capacitance of only 2.2 pF attains a -3-dB bandwidth of 220 MHz, which corresponds to a maximum nonreturn-to-zero data rate of 300 Mbit/s.

I. Introduction

THE performance of an optoelectronic integrated circuit (OEIC) in BiCMOS technology mainly depends on the characteristics of the integrated photodiode and the amplifier.