Image sensor structure

Abstract

The invention provides an image sensor structure. The image sensor structure comprises a pixel unit, a peripheral circuit and an auxiliary capacitor module, the peripheral circuit comprises a transmission tube, a reset tube, a source follower and a row selection tube; each pixel unit comprises a photodiode and a floating diffusion node; the photodiode and the floating diffusion node are both located in the substrate, and the transmission tube is fixed to the upper surface of the substrate and right faces the position between the photodiode and the floating diffusion node. The photodiode is connected with the floating diffusion node through the transmission tube. The other end of the floating diffusion node is connected with the source electrode of the reset tube and the grid electrode of the source follower. Drain electrodes of the source follower and the reset tube are connected to a bias voltage VDD, a source electrode of the source follower is connected with a drain electrode of the row selection tube, and a source electrode of the row selection tube is column-level output of a signal; each floating diffusion node is connected in parallel with an auxiliary capacitor module; and the control unit is integrated in the peripheral circuit. By dynamically adjusting the floating diffusion node capacity, the halo phenomenon is reduced, and the dynamic range is widened.

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