Method for automatically adjusting silicon wafer grinding pressure of chemical-mechanical polisher

Abstract

A method for automatically regulating the grinding pressure of chemicomechanical polishing machine to silicon wafer includes such steps as installing a pressure sensor in HCLU, installing a new retainer ring, setting up the thickness value of said retainer ring, turning the grinding head to a position above HCLU, measuring and automatically recording the pressure value on the new retainer ring, beginning to grind, unloading the silicon wafer while measuring the thickness of retainer ring, calculating the compensating value of pressure according to difference in thickness, and regulating pressure.

Description

technical field [0001] The invention relates to a chemical mechanical polishing (CMP) process in the field of semiconductor integrated circuit manufacturing, in particular to a method for automatically adjusting the grinding pressure of a silicon wafer of a CMP device. Background technique [0002] Currently applied to the CMP equipment in the field of integrated circuit manufacturing, in order to expand the effective area of ​​the silicon wafer, when the silicon wafer is ground, the retainer ring (retainer ring) that keeps the silicon wafer is all in contact with the grinding pad (such as figure 1 ). Using this method, the invalid area around the silicon wafer is less than 3mm. But the resulting problem is: with the grinding of the silicon wafer, the retainer ring is also continuously worn and consumed and gradually becomes thinner, and the corresponding pressure on the grinding pad and the resulting deformation will also change. Therefore, during the entire service life ...

AI Technical Summary

Problems solved by technology

But the resulting problem is: with the grinding of the silicon wafer, the retainer ring is also continuously worn and consumed and gradually becomes thinner, and the corresponding pressure on the grinding pad and the resulting deformation will also change

Therefore, during the entire service life of the retainer ring, due to the continuous thinning of the thickness, the grinding rate around the silicon wafer is also constantly changing, and the process lacks stability.

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