Feedback control of a chemical mechanical polishing device providing manipulation of removal rate profiles
First Claim
1. A method of producing a target wafer thickness profile in a polishing operation, comprising:
- (a) providing a model for wafer polishing that defines a plurality of substantially annular regions on a wafer and identifies a wafer material removal rate in a polishing step for each of the regions, wherein the model is based on measurements of one or more wafers that have completed the polishing step; and
(b) polishing a wafer using a polishing recipe based on the model that generates a target thickness profile for each region.
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Abstract
A method of controlling surface non-uniformity of a wafer in a polishing operation includes (a) providing a model for a wafer polishing that defines a plurality of regions on a wafer and identifies a wafer material removal rate in a polishing step of a polishing process for each of the regions, wherein the polishing process comprises a plurality of polishing steps, (b) polishing a wafer using a first polishing recipe based upon an incoming wafer thickness profile, (c) determining a wafer thickness profile for the post-polished wafer of step (b), and (d)calculating an updated polishing recipe based upon the wafer thickness profile of step (c) and the model of step (a) to maintain a target wafer thickness profile. The model can information about the tool state to improve the model quality. The method can be used to provide feedback to a plurality of platen stations.
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Citations
28 Claims
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1. A method of producing a target wafer thickness profile in a polishing operation, comprising:
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(a) providing a model for wafer polishing that defines a plurality of substantially annular regions on a wafer and identifies a wafer material removal rate in a polishing step for each of the regions, wherein the model is based on measurements of one or more wafers that have completed the polishing step; and (b) polishing a wafer using a polishing recipe based on the model that generates a target thickness profile for each region. - View Dependent Claims (6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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2. A method of controlling surface non-uniformity of a wafer in a polishing operation, comprising:
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(a) providing a model for wafer polishing that defines a plurality of regions on a wafer and a plurality of polishing steps and identifies a wafer material removal rate in a polishing step of a polishing process for each of the regions; (b) polishing a wafer using a first polishing recipe; (c) determining a wafer thickness profile for the polished wafer of step (b); and (d) calculating an updated polishing model based upon the wafer thickness profile of step (c) and the model of step (a) and updating the first polishing recipe based on the updated mode to maintain a target wafer thickness profile. - View Dependent Claims (3, 4, 5, 20)
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21. A method of determining a model for wafer thickness profile, comprising:
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(a) measuring pre-polished wafer thickness in each of a plurality of regions defined on one or more wafers; (b) polishing the one or more wafers, wherein polishing comprises polishing the one or more wafers in a plurality of polishing steps; (c) measuring the wafer material removal rate for the one or more wafers at each of the plurality of regions after each of the polishing steps of step (b); (d) providing a model defining the effect of tool state on polishing effectiveness; and (e) recording the pre-polished and post-polished wafer thicknesses for each of the regions on a recordable medium. - View Dependent Claims (22, 23, 24, 25, 26, 27)
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28. A method of producing a target wafer thickness profile in a polishing operation, comprising:
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(a) providing a model for wafer polishing that defines a plurality of substantially annular regions on a wafer, identifies a wafer material removal rate in a polishing step for each of the regions, and defines the effect of tool state on polishing effectiveness; and (b) polishing a wafer using a polishing recipe based on the model that generates a target thickness profile for each region.
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Specification