Noise characterization of megapixel quanta image sensor for scientific applications

Abstract

The quanta image sensor (QIS) is a novel CMOS-based image sensor capable of photon counting without the necessity of avalanche gain. The QIS reported in this work is implemented in a state-of-the-art backside-illuminated (BSI) CMOS image sensor commercial stacking (3D) process. The detector wafer consists of a megapixel array of specialized active pixels known as “jots” and the ASIC readout wafer utilizes cluster-based readout circuitry. This specialized pixel architecture and cluster readout circuits allow for the QIS to achieve accurate photon-counting capabilities with average read noise of 0.23e- rms, average conversion gain of 345μV/e-, and average dark current less than 0.1e-/sec/jot at room temperature without active cooling.