A high-Sensitivity and Wide Dynamic-Range APD-CMOS Image Sensor

Abstract

We present a high-sensitivity CMOS image sensor with an avalanche multiplication of photoelectrons. The pixel structure contains a multiplication region formed by a p-n junction, which is located between a photoelectric conversion region and a charge-storage region in a silicon substrate. Photoelectrons can be multiplied to 10^5 times before transferring to readout circuits. The present sensor can reproduce a natural color imaging under a dark illumination condition of 0.01 lux, and can also realize a high dynamic-range imaging of 100dB by controlling the multiplication factor. All the components including a multiplication region and transistors are constructed in one substrate, and thus we have realized a megapixel APD-CMOS image sensor with a 3.8μm pixel size.