CMOS image sensor with non-contact structure

摘要

A complementary metal oxide semiconductor (CMOS) image sensor device includes a capacitive coupled photodiode that is formed within a region of a semiconductor substrate. The photodiode receives an incident light and generates a corresponding electric charge. The CMOS image sensor device includes a reset transistor coupled to the photodiode for reverse biasing the photodiode with a predetermined voltage. The CMOS image sensor device further includes a buffer circuit and a capacitor, which is interposed between the photodiode and the buffer circuit. The capacitor is configured to transfer the electric charge to the buffer circuit. The buffer circuit may include an emitter follower or a source follower transistor.