Image sensor and forming method thereof

Abstract

An image sensor and a method for forming the same are provided. The image sensor includes a semiconductor substrate in which a logic device is formed; a metal interconnect layer located on a surface of the semiconductor substrate, the metal interconnect layer having a metal interconnect structure therein; a plurality of photoelectric conversion blocks located on a surface of the metal interconnectlayer, each photoelectric conversion block comprising at least three layers of a stacked photoelectric conversion structure, each photoelectric conversion structure comprising a photoelectric conversion layer and a connection structure, wherein different photoelectric conversion layers are electrically connected to different logic devices via the connection structure and the metal interconnect structure. The scheme of the invention can form more photogenerated carriers, reduce damage to the semiconductor substrate, reduce production cost and reduce process complexity.

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] Taking Back-side Illumination (BSI) CIS as an example, in the existing manufacturing process, logic devices and pixel devices are first formed in the semiconductor substrate and a metal interconnection structure is formed on the surface of the semiconductor substrate, and then the The carrying wafer is bonded to the front side of the semiconductor substrate, and then the back of the semiconductor substrate is thinned, a...

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Problems solved by technology

[0005] 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 The formation of photogenerated carriers is less; and in the process of forming the filter matrix, the production cost is high due to the high price of the raw materials of the filter

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