Laser Radar Imager Based on 3D Integration of Geiger-Mode Avalanche Photodiodes with Two SOI Timing Circuit Layers

Abstract

A 64 X 64 laser-radar (ladar) detector array with 50mum pixel size measures the arrival times of single photons using Geiger-mode avalanche photodiodes (APD). A 3-tier structure with active devices on each tier is used with 227 transistors, six 3D vias and an APD in each pixel. A 9b pseudorandom counter in the pixel measures time. Initial imagery shows 2ns time quantization