CMP process control method and control system thereof

Abstract

The invention discloses a CMP process control method and a control system thereof. A CMP process comprises grinding processes of a dielectric layer in a wafer and a grinding barrier layer located below the dielectric layer. According to the control method, a grinding amount correction value delta d which meets the formula of delta d=(D0-D2-D1)*k is introduced, wherein D0 is the initial thickness of the grinding barrier layer, D2 is the final thickness of the grinding barrier layer after grinding, D1 is the removal target value of the grinding barrier layer, and k is the selection ratio of thegrinding barrier layer, and therefore, the grinding amount correction value delta d can be obtained by taking the removal target value D1 of the grinding barrier layer as a reference through the control method, then the grinding amount d2 is continuously updated and corrected, the control system forms a closed-loop system with a correction value, the accurate control on the grinding amount d2 canbe achieved, the uniformity of the grinding thickness in the semiconductor manufacturing process is improved, and the performance of a semiconductor device is improved.

Description

technical field [0001] The present invention relates to the technical field of semiconductors, in particular to a control method and a control system for a CMP (Chemical Mechanical Planarization, chemical mechanical planarization) process. Background technique [0002] The CMP process is an important process in the manufacture of semiconductor devices. It uses the synergistic effect of chemical etching and mechanical grinding to effectively take into account the local and global flatness of semiconductor devices. [0003] At present, the control methods of the CMP process mainly include the direct use of fixed time (By time) grinding method and endpoint monitoring (endpoint) grinding method, such as the use of optical ISRM (In Situ Rate Monitor, in situ detection) endpoint detection system, Or use a TCM (Table Current Monitor, table current monitoring) detection system to monitor the grinding method of the end point. However, when the fixed-time grinding method is directly ...

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Problems solved by technology

However, when the fixed-time grinding method is directly used, since the grinding rate varies greatly with the service life of the consumables, the fixed-time grinding method has poor control over the removal of the grinding amount in the process; when using optical ISRM endpoint monitoring In the grinding method, it is sometimes difficult to accurately distinguish the end point signal due to the optical end point detection method, which leads to a high failure rate and affects the performance of semiconductor devices; in addition, the machine is transformed into a TCM that converts frictional force into a current signal The grinding method of the detection system not only requires additional modification costs, but also has a high failure rate, resulting in poor performance of semiconductor devices

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