Wafer Thinning Methods

Abstract

The invention discloses a wafer thinning method. The wafer thinning method comprises the following steps: providing a device wafer, wherein the device wafer comprises a front face and a back face opposite to the front face; performing a first crystal edge grinding process on the device wafer, and grinding the crystal edge of the device wafer so as to form a side wall on the crystal edge of the device wafer, wherein the side wall is at least connected with the front face of the device wafer; forming a protective layer on the side wall of the device wafer; laminating the device wafer to a bearing wafer, wherein the front face of the device wafer faces the bearing wafer; performing a thinning process on the back face of the device wafer and the protective layer on the side wall of the device wafer; carrying out a second crystal edge grinding process, and removing the protective layer on the side wall of the device wafer. By using the manufacturing method disclosed by the invention, the defects such as peeling and silicon damage formed during wafer thinning can be reduced or avoided.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a wafer thinning method. Background technique [0002] In the field of semiconductor manufacturing, after the device structure is prepared on the front side of the device wafer, the back side of the device wafer needs to be thinned. Since the thinned wafer can facilitate packaging and effectively transmit light, etc., the wafer The thinning process has become an important process in the field of semiconductor manufacturing, such as the field of integrated circuits. [0003] In the prior art, common wafer thinning methods include: [0004] First, performing a wafer edge grinding process on the device wafer, grinding the wafer edge of the device wafer to form a sidewall on the wafer edge of the device wafer; [0005] Next, bonding the device wafer to a carrier wafer, wherein the front side of the device wafer faces the carrier wafer; [0006] Next, perform a ...

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Problems solved by technology

In the process of performing the thinning process on the back side of the device wafer afterwards, the wet etching solution will corrode the metal structure on the crystal edge of the device wafer, and the etching rate of the wet etching solution to the metal structure is greater than The etch rate of the substrate material on the back side of the device wafer, so that defects affect the progress of subsequent processes

[0008] In order to reduce the above-mentioned defects, a grinding process is performed after the wet etching process in the prior art, but this grinding process only improves the smoothness of the wafer surface, and does not reduce or avoid the peeling formed when the wafer is thinned (peeling), silicon damage (Si damage) and other defects

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