System and method for online detecting service life of polishing pad

Abstract

The invention relates to a system and method for online detecting of service life of a polishing pad. According to the system and the method, the polishing pad with a groove is arranged on the surfaceof a polishing table and rotates along with the polishing table; a polishing head presses a wafer on the surface of the polishing pad and moves relative to the polishing table to flatten the wafer, specifically, a component corresponding to the polishing area is provided with a light source and an optical detector, and the light source emits light beams to the surface of the polishing pad and reflects the light beams to the optical detector; and a controller receives a signal from the optical detector on line, calculates the depth of the groove according to the strength of the signal, and judges the residual working time of the polishing pad. The invention also provides a CMP process parameter on-line adjusting method based on the service life detecting of the polishing pad, wherein the CMP process parameter, such as the planarization time, is adjusted on-line according to the residual working time of the polishing pad. The factors such as the rotation speed of the polishing table, the rotation speed of the polishing head, the pressure of the polishing head, the flow of polishing liquid and the temperature of the polishing disc can control the wafer planarization removal efficiency, so that the planarization efficiency and the planarization quality of the wafer are improved.

Description

technical field [0001] The invention relates to the field of equipment for manufacturing semiconductor integrated circuit chips, in particular to a system and method for online detection of the life of a polishing pad. Background technique [0002] Chemical mechanical planarization (Chemical Mechanical Planarization, CMP) is a process technology capable of achieving global and local planarization of semiconductor elements (such as wafers). [0003] The CMP equipment includes a polishing table, the surface of the polishing table is provided with a polishing pad; above the polishing table, a polishing head is provided to clamp the wafer to be processed, and a certain pressure is applied to press the wafer tightly against the surface of the polishing pad. surface; the polishing head and the polishing table move or rotate relative to each other, and at the same time, the polishing liquid composed of abrasive grains and chemical solution flows between the wafer and the polishing ...

AI Technical Summary

Problems solved by technology

[0009] Among them, the disadvantage of methods 1 and 2 is that, due to fluctuations in parameters such as the speed of the polishing table, the speed of the polishing head, the flow rate of the polishing liquid, and the temperature, it is easy to cause the wear of the polishing pad under the same working time or the same number of planarized wafers Inconsistency, replacing the polishing pad too early will easily cause waste, and replacing the polishing pad too late will easily lead to a decrease in product yield and yield

The disadvantage of method 3 is that it is necessary to manually measure the groove depth of the polishing pad, which will cause contamination of the polishing pad and reduce production efficiency

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