A Charge-Multiplication CMOS Image Sensor Suitable for Low-Light-Level Imaging

A highly sensitive charge-multiplication CMOS image sensor was fabricated. The 10 ¿m pixel pitch and CIF image format sensor has an array of unit pixels comprising photodiode region, charge multiplication unit, and source follower charge-to-voltage conversion circuit within each pixel. Thanks to the well-controlled charge multiplication sequence utilizing CCD charge transfer technology, a high efficiency signal multiplication was achieved without significant increase of charge multiplication noises. And there is little dispersion of multiplication gain in the whole imaging area so suitable dark-field imaging of about 0.4 1x has been achieved.