Wafer Edge Chip Planarization Method

Abstract

The invention discloses a wafer edge chip flattening method. The method comprises the steps that a wafer to be ground is provided, and a plurality of chips to be ground are distributed on the wafer to be ground; the wafer to be ground is adsorbed to a grinding head, the grinding head is provided with an edge area and a center area, the downward pressure in the edge area of the grinding head is exerted on the edge area of the wafer to be ground, and the downward pressure in the center area of the grinding head is exerted on the center area of the wafer to be ground; the grinding head to which the wafer to be ground is adsorbed is moved to a grinding cushion; the downward pressure in the edge area of the grinding head is set to range from 4.5 psi to 6.0 psi, the downward pressure in the center area of the grinding head is set to range from 3.5 psi to 4.5 psi, the revolving speed of a rotary table is set to range from 100 rpm to 150 rpm, and the chips to be ground are ground to be with the thickness changing from the initial value to the first set value; the downward pressure in the edge area of the grinding head is set to range from 0.8 psi to 1.5 psi, the downward pressure in the center area of the grinding head is set to range from 0.7 psi to 1.2 psi, the revolving speed of the rotary table is set to range from 100 rpm to 150 rpm, and the chips to be ground are ground to be with the thickness changing from the first set value to the target value.

Description

technical field [0001] The invention relates to the technical field of integrated circuit manufacturing, in particular to a wafer edge chip planarization method. Background technique [0002] In the current integrated circuit manufacturing process, chemical mechanical polishing (CMP) is still an important planarization technology. Chemical mechanical polishing uses a combination of chemical reaction and mechanical polishing to planarize wafers with uneven surfaces. The process is as follows: First, the wafer to be polished is adsorbed under the grinding head, and then a downward force is applied to the grinding head. pressure, so that the surface of the wafer to be polished is pressed tightly on the polishing pad, and then the turntable with the polishing pad on the surface rotates under the drive of the motor. At the same time, the grinding head also rotates in the same direction. When the grinding head and the turntable rotate , the polishing liquid is supplied to the pol...

AI Technical Summary

Problems solved by technology

In a small area, if the surface of the wafer 100 is uneven, the pattern will not be clearly transferred to the wafer 100, resulting in exposure failure, and finally resulting in unusable chips on the wafer

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