Image sensor and formation method thereof

Abstract

Disclosed are an image sensor and a formation method thereof. The image sensor comprises a semiconductor substrate, a metal interconnection layer, at least three layers of stacked photoelectric conversion layers, and a liner structure, wherein logic devices and a unidirectional conduction structure are formed in the semiconductor substrate; the metal interconnection layer is located on the surfaceof the semiconductor substrate, wherein a drain interconnection structure and a logic interconnection structure are arranged in the metal interconnection layer; the at least three layers of stacked photoelectric conversion layers are located on the surface of the metal interconnection layer, wherein the different photoelectric conversion layers are electrically connected to different logic devices through the logic interconnection structure; and the liner structure which is positioned on the surfaces of at least three layers of stacked photoelectric conversion layers, wherein the at least three layers of stacked photoelectric conversion layers are electrically connected with the liner structure through the drain interconnection structure and the unidirectional conduction structure. By virtue of the scheme, photon-generated carriers in the photoelectric conversion layers can be guided out, so that the possibility of image streaking is lowered.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to an image sensor and a forming method thereof. Background technique [0002] The image sensor is the core component of the camera equipment, which realizes the image capture function by converting the optical signal into an electrical signal. Taking a CMOS image sensor (CMOS Image Sensors, CIS) device as an example, due to its advantages of low power consumption and high signal-to-noise ratio, it has been widely used in various fields. [0003] However, in the prior art, the ion implantation process is used to form the photodiode (PhotoDiode, PD) in the pixel device, which is easy to cause damage to the semiconductor substrate, and the size of the manual pixel device is limited, and the size of the photodiode is often small, resulting in There are fewer photogenerated carriers; and in the process of forming the optical filter matrix, the production cost is rel...

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Problems solved by technology

[0005] However, in the above-mentioned image sensor, the photogenerated carriers need to travel a long path to be transported to the logic device, and it is easy to cause the problem that the photogenerated carriers generated during the previous illumination remain in the photoelectric conversion layer, resulting in the formation of The image of the image is affected, and the problem of image smearing occurs

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