Method of controlling plasma etch process
First Claim
1. A method for automated monitoring and controlling of a semiconductor wafer plasma etching process comprising the steps of:
- collecting data versus time during a plasma etching process said data including information representative of a concentration of at least one pair of reactant and product species present during the course of the plasma etching process;
calculating a selected ratio of at least one reactant species and one product species at selected time intervals in the plasma etching process to create real-time reactant-product ratio data;
retrieving pre-determined reactant-product ratio data for the at least one reactant species and one product species for comparison with the real-time reactant-product ratio data;
comparing the pre-determined reactant-product ratio data with the real-time reactant-product ratio data to determine a difference; and
adjusting at least one plasma process operating parameter to minimize the difference.
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Accused Products
Abstract
A method for automated monitoring and controlling of a semiconductor wafer plasma etching process including collecting data versus time during a plasma etching process said data including information representative of a concentration of at least one pair of reactant and product species present during the course of the plasma etching process; calculating a selected ratio of at least one reactant species and one product species at selected time intervals in the plasma etching process to create real-time reactant-product ratio data; retrieving pre-determined reactant-product ratio data for the at least one reactant species and one product species for comparison with the real-time reactant-product ratio data; comparing the pre-determined reactant-product ratio data with the real-time reactant-product ratio data to determine a difference; and, adjusting at least one plasma process operating parameter to minimize the difference.
3 Citations
20 Claims
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1. A method for automated monitoring and controlling of a semiconductor wafer plasma etching process comprising the steps of:
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collecting data versus time during a plasma etching process said data including information representative of a concentration of at least one pair of reactant and product species present during the course of the plasma etching process;
calculating a selected ratio of at least one reactant species and one product species at selected time intervals in the plasma etching process to create real-time reactant-product ratio data;
retrieving pre-determined reactant-product ratio data for the at least one reactant species and one product species for comparison with the real-time reactant-product ratio data;
comparing the pre-determined reactant-product ratio data with the real-time reactant-product ratio data to determine a difference; and
adjusting at least one plasma process operating parameter to minimize the difference. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method for automated monitoring and controlling of a semiconductor wafer plasma etching process independently of an etching pattern density comprising the steps of:
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collecting data versus time during a plasma etching process said data including information representative of a concentration of at least one pair of reactant and product species present during the course of the plasma etching process;
a calculating a selected ratio of at least one reactant species and one product species at selected time intervals in the plasma etching process to create real-time reactant-product ratio data;
retrieving pre-determined reactant-product ratio data for the at least one reactant species and one product species for comparison with the real-time reactant-product ratio data;
comparing the pre-determined reactant-product ratio data with the real-time reactant-product ratio data to determine a difference; and
selectively adjusting at least one plasma process operating parameter. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19)
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20. The method of clam 12, wherein the step of comparing is performed using statistical methods including non-linear least squares and multi-variant analysis.
Specification