Semiconductor device and method of manufacturing the same

Abstract

The present invention provides a semiconductor device and a method for manufacturing the same. The method for manufacturing the semiconductor device includes: forming a trench filling structure in a substrate of a pixel region, and filling material in the trench filling structure with sidewalls and the substrate A high-K dielectric layer is also sandwiched therebetween; the buffer dielectric layer is covered on the substrate surface of the pixel region, and the buffer dielectric layer buries the trench filling structure; the buffer dielectric layer is etched to form at least the trench filling Part of the substrate and / or the trench at the periphery of the top sidewall of the structure fills at least part of the first opening at the top of the structure; and, forming a metal grid layer on the buffer dielectric layer and filling the first opening so as to be compatible with the exposed part The substrate and / or the trench filling structure are electrically connected. The technical solution of the present invention enables the metal grid layer to be electrically connected to the exposed part of the substrate and / or the trench filling structure, thereby enabling optimization and improvement of the electrical performance of the semiconductor device.

Description

technical field [0001] The invention relates to the field of semiconductor integrated circuit manufacturing, in particular to a semiconductor device and a manufacturing method thereof. Background technique [0002] In the manufacturing process of Back-side Illumination CMOS Imagination Sensor (BSI-CIS), deep trench isolation (Deep Trench Isolation, DTI) technology and Backside Metal Grid (BMG for short) ) technology can make the back-illuminated CMOS image sensor have better optical performance. [0003] However, in the existing process of fabricating a back-illuminated CMOS image sensor, there is a buffer medium layer between the fabricated metal grid in the pixel region and the underlying substrate and the deep trench filling structure, so that the metal grid is connected to the underlying substrate and the deep trench filling structure. The substrate and the deep trench filling structure are only physically connected, and cannot be electrically connected, so that it is i...

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Problems solved by technology

[0003] However, in the existing process of making a back-illuminated CMOS image sensor, there is a buffer medium layer between the metal grid in the pixel area and the underlying substrate and deep trench filling structure, so that the metal grid and the underlying There is only a physical connection between the substrate and the deep trench filling structure, but no electrical connection, which makes it impossible to optimize and improve the electrical performance of the back-illuminated CMOS image sensor

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