A SPAD Based QVGA Image Sensor for Single Photon Counting and Quanta Imaging
A CMOS single photon avalanche diode (SPAD) based quarter video graphics array image sensor with 8 mm pixel pitch and 26.8% fill factor (FF) is presented. The combination of analog pixel electronics and scalable shared well SPAD devices facilitates high resolution, high FF SPAD imaging arrays exhibiting photon shot noise limited statistics. The SPAD has 47 counts/s dark count rate at 1.5 V excess bias (EB) 39.5% photon detection probability (PDP) at 480 nm, and a minimum of 1.1 ns dead time at 1 V EB. Analog single photon counting imaging is demonstrated with maximum 14.2 mV/SPAD event sensitivity and 0.06e minimum equivalent read noise. Binary quanta image sensor (QIS) 16 kframes/s real time oversampling is shown, verifying single photon QIS theory with 4.6x overexposure latitude and 0.168e read noise.
IEEE Transactions on Electron Devices