Preparation method of image sensor

• Main Authors: QIN YOUHUA, CHEN HAOYU, JI FENG
• Format: Patent
• Language: Chinese; English
• Published: 01.02.2022
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

The invention provides a preparation method of an image sensor, which comprises the steps of providing a substrate, wherein the substrate comprises a pixel area and a logic area located on the periphery of the pixel area, and an interconnection structure is formed in the logic area of the substrate; a metal layer is formed on the first surface of the substrate, the metal layer comprises a first part covering the pixel area and a second part covering the logic area, and the second part is electrically connected with the interconnection structure; etching the first part to form a plurality of through first grooves; forming a passivation layer on the metal layer conformally, and etching the passivation layer of the logic region to thin the passivation layer of the logic region; and conducting a planarization process on the passivation layer, and etching the passivation layer of the logic region before the planarization process, so that the thickness of the passivation layer of the logic region is reduced, the un