System and method for online detecting life of CMP polishing pad

Abstract

The invention relates to a system and a method for online detecting the life of a CMP polishing pad. According to the system and the method, the polishing pad provided with a groove is arranged on thesurface of a polishing table and rotates along with the polishing table; a wafer is pressed by a polishing head on the surface of the polishing pad, moves relative to the polishing table, and is subjected to flattening treatment; a light source and an optical detector are mounted on a component in a corresponding polishing area; a light beam is emitted by the light source to the surface of the polishing pad and reflected to the optical detector; and a signal from the optical detector is online received by a controller, the depth of the groove is calculated by the controller according to the strength of the signal, and the remaining working time of the polishing pad is judged by the controller. The invention further provides a method for online adjusting CMP process parameters based on polishing pad life detection. According to the remaining working time of the polishing pad, the CMP process parameters such as the flattening time, the rotating speed of the polishing table, the rotatingspeed of the polishing head, the pressure of the polishing head, the flow rate of a polishing fluid, the temperature of a polishing disc, and other factors capable of controlling the wafer flatteningremoval efficiency can be adjusted online, and then the wafer flattening efficiency and flattening quality can be improved.

Description

technical field [0001] The invention relates to a system and a method for on-line detection of the life of a polishing pad, in particular to a system and a method for on-line detection of the life of a CMP polishing pad. Background technique [0002] Chemical mechanical polishing, also known as chemical mechanical planarization (CMP) or chemical mechanical polishing (CMP), is a process technology capable of achieving global and local planarization of semiconductor components (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 chemic...

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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