Pn photodiodes for pulsed laser rangefinding applications realized in standard CMOS/BiCMOS processes

Abstract

This paper describes simulation of the operation of integrated high-speed pn photodiodes and verification of the results by means of measurements performed with two types of photodiode, one implemented in a standard 0.8 μm CMOS process and the other in a standard 1.2 μm BiCMOS process. The measured rise times and responsivities of the photodiodes were <5 ns and 0.28 A/W in the CMOS process and 30 ns and 0.31 A/W in the BiCMOS process. Furthermore, the suitability of the photodiode for 3D vision was investigated by designing an array of photodetectors and measuring the isolation between the detector blocks. The results confirm that the photodetectors and receiver for a pulsed laser rangefinder can be implemented on the same chip in a standard process without any process modifications.