A 0.16e-rms Temporal Noise 0.015Hz/μm2 Dark Count Rate Charge Focusing SPAD Image Sensor for Low Light Imaging

摘要

We demonstrate a SPAD image sensor in 0.18μm CIS process for low light imaging, featuring 128×128 pixel array with global shutter function, in-pixel 16b digital counter, and output clipping circuit to suppress the black spot effect. On-chip Bayer color filter enabled the RGB color imaging at the single-photon signal level. The proposed charge focusing SPAD achieved the max. PDP of 40% and DCR density of 0.015Hz/μm~2 at 2.5V excess bias. The temporal noise of 0.16e-rms was obtained at 1/120s exposure.