A grinding method for preventing microscopic scratches during chemical mechanical grinding

Abstract

Disclosed is a grinding method capable of preventing microcosmic scratches during chemical mechanical grinding. The grinding method includes subjecting wafers to primary coarse grinding on a first grinding platform, secondary coarse grinding on a second grinding platform and streamline grinding of fine grinding in sequence, starting fine grinding by adding a grinding liquid supply system when one third to one fourth of the total thickness of the surfaces of the wafers to be ground is left, and beginning putting the added grinding liquid supply system into use. The grinding liquid supply system is used only during fine grinding and only when granularity in the grinding liquid is not larger than one second of that during coarse grinding; by the grinding method, on the premise of not affecting chemical mechanical grinding efficiency, fine grinding by small-diameter grinding particles can restore scratches on the surfaces of the wafers due to large-diameter grinding particles during coarse grinding, so that quality of the wafers is improved and service lives of the wafers are prolonged.

Description

technical field [0001] The invention relates to the technical field of integrated circuit manufacturing, and more specifically relates to a chemical mechanical polishing method for preventing wafer microscopic scratches. Background technique [0002] In the wafer production process of integrated circuits, it is necessary to use a chemical mechanical grinding machine to grind the wafer so as to flatten the wafer surface as a whole. Such as figure 1 , figure 1 is a top view of a grinding machine with different grinding platforms; figure 1 Among them, the wafer carrier 13 absorbs the wafer loaded by the wafer loading device 21 in the form of vacuum negative pressure, and the rotating shaft 12 of the wafer carrier can move the wafer carrier 13 and the wafer it holds from the carrier After entering the position, transfer to the first grinding platform 11 for grinding, then transfer to the second grinding platform 10 for grinding, and then transfer to the wafer post-processing ...

AI Technical Summary

Problems solved by technology

[0005] However, it is clear to those skilled in the art that the current chemical mechanical polishing method of sharing a polishing liquid on the two polishing platforms, especially in the wafer manufacturing process below 40nm, contains a relatively large amount of grinding liquid in the polishing liquid. Although the particles improve the grinding efficiency, they will cause microscopic scratches on the surface of the wafer, reducing the success rate of wafer manufacturing and reducing the service life of the wafer

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