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 according to at least one of optical emission spectroscopy and mass spectroscopy during a plasma etching process said data representative of a concentration of at least one reactant and one product species present during the course of the plasma etching process;
calculating a concentration ratio comprising the at least one reactant species and one product species at selected time intervals during the plasma etching process to create real-time concentration ratio data;
retrieving model concentration ratio data determined according to a model etching process for the at least one reactant species and one product species;
comparing the model concentration ratio data with the real-time concentration ratio data; and
, adjusting in-situ at least one plasma process operating parameter in response to the real-time concentration ratio to approach the model reactant-product concentration ratio.
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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 the 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 concentration ratio data; retrieving model concentration ratio data for the at least one reactant species and one product species for comparison with the real-time concentration ratio data; comparing the model concentration ratio data with the real-time concentration ratio data to determine a difference; and, adjusting at least one plasma process operating parameter to minimize the difference.
25 Citations
17 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 according to at least one of optical emission spectroscopy and mass spectroscopy during a plasma etching process said data representative of a concentration of at least one reactant and one product species present during the course of the plasma etching process;
calculating a concentration ratio comprising the at least one reactant species and one product species at selected time intervals during the plasma etching process to create real-time concentration ratio data;
retrieving model concentration ratio data determined according to a model etching process for the at least one reactant species and one product species;
comparing the model concentration ratio data with the real-time concentration ratio data; and
,adjusting in-situ at least one plasma process operating parameter in response to the real-time concentration ratio to approach the model reactant-product concentration ratio. - View Dependent Claims (2, 3, 4, 5, 6, 12, 13, 14, 15, 16, 17)
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7. 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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determining concentration versus time during a plasma etching process of at least one reactant and one product species present during the plasma etching process according to at least one of optical emission spectroscopy and mass spectroscopy;
calculating a concentration ratio selected from the group consisting of a reactant-product ratio and product-reactant ratio of the at least one reactant species and one product species at selected time intervals during the plasma etching process to determine real-time concentration ratio data;
retrieving model concentration ratio data comprising the at least one reactant species and one product species to determine a desired concentration ratio;
comparing the model concentration ratio data with the real-time concentration ratio data to determine a desired concentration ratio; and
,selectively adjusting at least one plasma process operating parameter in-situ to approach the desired concentration ratio. - View Dependent Claims (8, 9, 10, 11)
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Specification