IMAGE SENSOR PIXEL HAVING PINNED PHOTODIODE WITH COUPLING CAPACITOR AND METHOD FOR SENSING A SIGNAL THEREOF

摘要

A pinned photodiode with a coupling capacitor and an image sensor using it. The pinned photodiode with the coupling capacitor comprises a first diffusion region having a second conductive type formed in an epitaxial layer having a first conductive type; a second diffusion region having a first conductive type formed over the first diffusion region; a third diffusion region having a second conductive type formed in the epitaxial layer and connected to the first diffusion region; a fourth diffusion region having a first conductive type formed in the third diffusion region; and a coupling capacitor connected to the fourth diffusion region to couple the voltage change of the third diffusion region to the outside. The image sensor comprises the pinned photodiode described above, a reset switch, a multi-functional switch between a variable voltage source and an output terminal of the coupling capacitor, and a signal amplifier.