Method making back of wafer flat

Abstract

The invention relates to the manufacture field of semiconductors, in particular to a method making a back of a wafer flat. The method comprises the following steps: a slide glass wafer is bonded with a device wafer through a bonding oxidizing material; the device wafer is deburred to enable edges of the device wafer to be smooth and evasive; the back of the device wafer is caught out mechanical lapping, and the thickness of the device wafer is lapped to be 25 microns -50 microns; the back of the device wafer is processed through a chemical method, and the thickness of the device wafer is further reduced to 2 microns-3 microns. Monox which has a hard character is etched through a chemical etching method. For a process with thickness requirements which is high in accuracy, chemical lapping is easier to control than the mechanical lapping, and particulate pollution cannot be polluted.

Description

Technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a method for flattening the back of a wafer. Background technique [0002] The wafer thinning process has a wide range of applications in some advanced technologies, such as 3D IC (three-dimensional integrated circuit), back-illuminated image sensor and so on. The upper part of the wafer is used to conduct each wafer, and the polishing process is used on the back of the wafer (the surface opposite to the upper part), and the polishing includes mechanical polishing and chemical polishing. [0003] However, the flattening of the backside of the wafer is a huge challenge. At present, mechanical polishing is used to thin the back of the wafer, but mechanical polishing has many disadvantages. For example, it is difficult to reduce the thickness of the wafer to 2um, and mechanical polishing is likely to cause defects such as scratches. The main component of the edge of the wafer i...

AI Technical Summary

Problems solved by technology

[0003] However, the planarization of its wafer backside is a huge challenge

At present, mechanical grinding is used to thin the back of the wafer, but there are many disadvantages in the use of mechanical grinding, for example, it is difficult to reduce the thickness of the wafer to 2um, and mechanical grinding is easy to cause defects, such as scratches, etc.

The main component of the edge of the wafer is silicon oxide. When trimming the wafer, the method of mechanical grinding is not easy to control and will cause particle pollution.

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