Feedback control of chemical mechanical polishing device providing manipulation of removal rate profiles
First Claim
1. An apparatus for polishing substrates, comprising:
- at least one polishing station configured to polish a current wafer during a polishing process; and
a controller, operatively coupled to the at least one polishing station, configured to control the polishing station during the polishing process, to receive data relating to material removal rates for a plurality of substantially annular regions on the wafer, to predict a material removal rate for each of the plurality of substantially annular regions using a wafer polishing model that is based on measurement of one or more previous wafers that have completed at least one step of the polishing process, wherein the wafer polishing model defines an effect of a tool state of the at least one polishing station on polishing effectiveness based on applying a scaling factor that depends on pad life and disk life, to calculate differences between the predicted material removal rates and actual material removal rates that are determined based on the received data, to update the wafer polishing model based on the calculated differences, and to adjust a processing parameter of the polishing process based on the updated wafer polishing model.
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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.
401 Citations
16 Claims
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1. An apparatus for polishing substrates, comprising:
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at least one polishing station configured to polish a current wafer during a polishing process; and a controller, operatively coupled to the at least one polishing station, configured to control the polishing station during the polishing process, to receive data relating to material removal rates for a plurality of substantially annular regions on the wafer, to predict a material removal rate for each of the plurality of substantially annular regions using a wafer polishing model that is based on measurement of one or more previous wafers that have completed at least one step of the polishing process, wherein the wafer polishing model defines an effect of a tool state of the at least one polishing station on polishing effectiveness based on applying a scaling factor that depends on pad life and disk life, to calculate differences between the predicted material removal rates and actual material removal rates that are determined based on the received data, to update the wafer polishing model based on the calculated differences, and to adjust a processing parameter of the polishing process based on the updated wafer polishing model. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. An apparatus comprising:
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at least one polishing station configured to polish a current wafer; and a control station configured to use a polishing recipe to control the at least one polishing station to polish the wafer, wherein the polishing recipe is based on a wafer polishing model 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 wafer polishing model is based on measurements of one or more previous wafers that have completed the polishing step, wherein the wafer polishing model defines an effect of a tool state of the at least one polishing station on polishing effectiveness based on applying a factor that depends on pad life and disk life, and wherein the wafer polishing model generates a target thickness profile for each region. - View Dependent Claims (15, 16)
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Specification