Run-to-run control utilizing virtual metrology in semiconductor manufacturing
First Claim
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1. A method for run-to-run control and sampling optimization in a semiconductor manufacturing process, the method comprising steps of:
- determining a process output and corresponding metrology error associated with an actual metrology for a current processing run in the semiconductor manufacturing process;
determining a predicted process output and corresponding prediction error associated with a virtual metrology for the current semiconductor manufacturing processing run;
assigning a first weight to the metrology error and a second weight to the prediction error, the first and second weights being indicative of a confidence in the metrology error and prediction error, respectively; and
controlling at least one parameter corresponding to a subsequent semiconductor manufacturing processing run as a function of the metrology error, the first and second weights, and the prediction error;
wherein said semiconductor manufacturing process is executed to fabricate at least one wafer.
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Abstract
A method for run-to-run control and sampling optimization in a semiconductor manufacturing process includes the steps of: determining a process output and corresponding metrology error associated with an actual metrology for a current processing run in the semiconductor manufacturing process; determining a predicted process output and corresponding prediction error associated with a virtual metrology for the current processing run; and controlling at least one parameter corresponding to a subsequent processing run as a function of the metrology error and the prediction error.
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Citations
17 Claims
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1. A method for run-to-run control and sampling optimization in a semiconductor manufacturing process, the method comprising steps of:
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determining a process output and corresponding metrology error associated with an actual metrology for a current processing run in the semiconductor manufacturing process; determining a predicted process output and corresponding prediction error associated with a virtual metrology for the current semiconductor manufacturing processing run; assigning a first weight to the metrology error and a second weight to the prediction error, the first and second weights being indicative of a confidence in the metrology error and prediction error, respectively; and controlling at least one parameter corresponding to a subsequent semiconductor manufacturing processing run as a function of the metrology error, the first and second weights, and the prediction error; wherein said semiconductor manufacturing process is executed to fabricate at least one wafer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method for run-to-run control and sampling optimization in a semiconductor manufacturing process, the method comprising steps of:
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determining a process output and corresponding metrology error associated with an actual metrology for a current processing run in the semiconductor manufacturing process; determining a predicted process output and corresponding prediction error associated with a virtual metrology for the current semiconductor manufacturing processing run; and controlling at least one parameter corresponding to a subsequent semiconductor manufacturing processing run as a function of the metrology error and the prediction error; wherein the steps of determining the predicted process output and corresponding prediction error comprises; obtaining a prediction model associated with the semiconductor manufacturing process, the prediction model adapted to predict the process output by estimating at least one processing parameter for the semiconductor manufacturing process; and performing virtual metrology based on the prediction model, the prediction error being determined as a function of an output of the virtual metrology; wherein the prediction model comprises a wafer quality prediction model for metrology variable prediction which utilizes tensor input process variables by directly operating on the tensor input process variables.
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14. A method for run-to-run control and sampling optimization in a semiconductor manufacturing process, the method comprising steps of:
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determining a process output and corresponding metrology error associated with an actual metrology for a current processing run in the semiconductor manufacturing process; determining a predicted process output and corresponding prediction error associated with a virtual metrology for the current semiconductor manufacturing processing run; controlling at least one parameter corresponding to a subsequent semiconductor manufacturing processing run as a function of the metrology error and the prediction error; assigning a first weight to the metrology error and a second weight to the prediction error, the first and second weights being indicative of a confidence in the metrology error and prediction error, respectively; controlling the at least one parameter corresponding to a subsequent processing run as a function of the first and second weights; and optimizing a sampling policy corresponding to the semiconductor manufacturing process as a function of the first and second weights; wherein the step of optimizing the sampling policy comprises at least one of;
minimizing a sampling frequency of the semiconductor manufacturing process, the sampling frequency being indicative of at least one of a number of processing runs and a number of wafers between consecutive metrology measurements obtained during actual metrology; and
maximizing a time between actual metrology measurements obtained in connection with the semiconductor manufacturing process.
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15. A method for run-to-run control and sampling optimization in a semiconductor manufacturing process, the method comprising steps of:
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determining a process output and corresponding metrology error associated with an actual metrology for a current processing run in the semiconductor manufacturing process; determining a predicted process output and corresponding prediction error associated with a virtual metrology for the current semiconductor manufacturing processing run; controlling at least one parameter corresponding to a subsequent semiconductor manufacturing processing run as a function of the metrology error and the prediction error; assigning a first weight to the metrology error and a second weight to the prediction error, the first and second weights being indicative of a confidence in the metrology error and prediction error, respectively; controlling the at least one parameter corresponding to a subsequent processing run as a function of the first and second weights; and calculating a given one of the first and second weights according to an expression
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16. A method for run-to-run control and sampling optimization in a semiconductor manufacturing process, the method comprising steps of:
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determining a process output and corresponding metrology error associated with an actual metrology for a current processing run in the semiconductor manufacturing process; determining a predicted process output and corresponding prediction error associated with a virtual metrology for the current processing run; and controlling at least one parameter corresponding to a subsequent processing run as a function of the metrology error and the prediction error; wherein determining the predicted process output and corresponding prediction error comprises;
obtaining a prediction model associated with the semiconductor manufacturing process, the prediction model adapted to predict the process output by estimating at least one processing parameter for the semiconductor manufacturing process, the prediction model comprising a wafer quality prediction model for metrology variable prediction which utilizes tensor input process variables; and
performing virtual metrology based on the prediction model, the prediction error being determined as a function of an output of the virtual metrology.
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17. A method for run-to-run control and sampling optimization in a semiconductor manufacturing process, the method comprising steps of:
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determining a process output and corresponding metrology error associated with an actual metrology for a current processing run in the semiconductor manufacturing process; determining a predicted process output and corresponding prediction error associated with a virtual metrology for the current processing run; controlling at least one parameter corresponding to a subsequent processing run as a function of the metrology error and the prediction error; assigning a first weight to the metrology error and a second weight to the prediction error, the first and second weights being indicative of a confidence in the metrology error and prediction error, respectively; controlling the at least one parameter corresponding to a subsequent processing run as a function of the first and second weights; and optimizing a sampling policy corresponding to the semiconductor manufacturing process as a function of the first and second weights; wherein optimizing the sampling policy comprises at least one of;
minimizing a sampling frequency of the semiconductor manufacturing process, the sampling frequency being indicative of at least one of a number of processing runs and a number of wafers between consecutive metrology measurements obtained during actual metrology; and
maximizing a time between actual metrology measurements obtained in connection with the semiconductor manufacturing process.
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Specification