Method for controlling grinding process

Abstract

The invention discloses a method for controlling a grinding process. The grinding process comprises a main grinding step and an over-grinding step. The method comprises the following steps of: calculating a time range of the main grinding step according to the thickness of a layer to be ground; setting the maximum allowable time of the main grinding step, wherein the value of the maximum allowable time is greater than the maximum value of the main grinding time range; monitoring grinding time in the process of implementing a main grinding process; and immediately stopping the main grinding process when the implementation time of the main grinding step reaches the maximum allowable time. The method has the advantages that: the monitored grinding time is only the main grinding time and does not comprise over-grinding time; and because an over-grinding process is also actually required to be performed after the grinding end point is reached, the scrapping conditions of a wafer caused by over-grinding can be avoided as many as possible.

Description

【Technical field】 [0001] The invention relates to the field of semiconductor manufacturing, in particular to a method and device for controlling a grinding process. 【Background technique】 [0002] Chemical Mechanical Polishing (CMP) is a critical process in semiconductor processing. After the "main polishing" step, an "over polish" step is usually performed to ensure that there is no residue on the entire wafer surface. In many main etching steps of CMP, the method of catch endpoint is used to detect the change of film material, and in order to avoid the abnormality of CMP process or machine during grinding, CMP sets a "maximum grinding time" to Constrain and control the maximum time of grinding to ensure that it will not grind endlessly. The main grinding step and the over-grinding step of CMP are carried out continuously, so the current maximum grinding time is to set a delay on the basis of the above time, so what is controlled is the sum of these two parts of time. ...

AI Technical Summary

Problems solved by technology

[0003] The disadvantage of the existing technology is that the maximum grinding time is controlled by the total time, that is, the sum of the main grinding time and the over grinding time

If the maximum grinding time is set too large, then if the end point detection of the grinding process fails, it will continue to grind the part that has been ground, and then continue grinding until the set delay. At this time, the wafer is likely to be Excessive time leads to scrapping

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