Method and system for monitoring polishing pad
AssigneesSemiconductor Manufacturing International (Beijing) Corporation, Semiconductor Manufacturing International (Shanghai) Corporation
InventorChao Shi
Life of this patent
Estimating the term…
Abstract
Method and system for monitoring a polishing pad is provided. The polishing pad includes a bottom layer, a polishing layer disposed on the bottom layer, and a plurality of mark structures disposed on the bottom layer and in the polishing layer to have a top surface coplanar with the polishing layer to indicate consumption level of the polishing layer. The monitoring system includes an acquisition module, a memory module, and a determining module connected to both the acquisition module and the memory module. The determining module, the acquisition module, and the memory module are configured to monitor the consumption level of the polishing layer and to recognize that the polishing pad needs to be replaced.
Claims20
A method for monitoring a polishing pad, comprising:
- providing a polishing pad including a polishing layer disposed on a bottom layer, and a plurality of mark structures disposed on the bottom layer and in the polishing layer to have a top surface coplanar with the polishing layer to indicate a consumption level of the polishing layer, wherein the plurality of mark structures are configured to include mark patterns, each mark structure includes a plurality of mark layers stacked one over another to form a stacked structure, and a size of each mark layer in each mark structure becomes smaller along a direction away from a surface of the bottom layer;
- acquiring label graphs of a plurality of label structures;
- comparing each mark pattern with a pre-stored critical pattern to obtain the consumption level of the polishing layer in a region adjacent to the mark structure corresponding to the mark pattern, wherein the critical pattern is the mark pattern of a corresponding mark structure when the polishing layer is worn;
- recognizing that the polishing layer adjacent to a mark structure is worn every time when the mark pattern is identical to the corresponding critical pattern, and also adding one into a counting number, wherein the counting number is used to count the times that mark patterns match with corresponding critical patterns;
- and
- recognizing that the polishing pad needs to be replaced when the counting number reaches a preset value.
A monitoring system for monitoring a polishing pad, comprising:
- an acquisition module used to acquire mark patterns of a plurality of mark structures, wherein the polishing pad includes a polishing layer disposed on a bottom layer, and the plurality of mark structures disposed on the bottom layer and in the polishing layer to have a top surface coplanar with the polishing layer to indicate a consumption level of the polishing layer, wherein the plurality of mark structures are configured to include mark patterns, each mark structure includes a plurality of mark layers stacked one over another to form a stacked structure, and a size of each mark layer in each mark structure becomes smaller along a direction away from a surface of the bottom layer;
- a memory module used to store critical patterns and a preset value, wherein each critical pattern of the critical patterns is the mark pattern of the corresponding mark structure when the polishing pad is worn while the preset value is the number of times that mark patterns match with the corresponding critical patterns when the polishing pad is worn;
- and
- a determining module connected to the acquisition module and the memory module, wherein the determining module, together with the acquisition module and the memory module, are configured to compare the acquired mark patterns with the corresponding critical patterns, calculate the number of times that the critical patterns match the mark patterns, compare the preset value with the number of times that the critical patterns match with the mark patterns, and further recognize that the polishing pad needs to be replaced when the number of times that the critical patterns match with the mark patterns reaches the preset value.
Dependencies are inferred from the claim text.