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US 12,635,454 B2Granted
Systems and methods for determining residual compounds in plasma process
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsChen-Tai Chen, Jing-Ran Lin, Jer-Shien Yang, Hung-Wen Chen, I-Ling Kuo, Yu-Hsun Chiang
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Abstract
The present disclosure provides a system and method for predicting wafer fabrication defects resulting from plasma processing of wafers in a plasma processing chamber. The system and method include processing electromagnetic signals emitted from residual compounds peeled from the chamber walls during the plasma processing of the wafers to indirectly determine the likelihood that the wafers are incurring fabrication processing defects during the plasma processing.
Claims20
A method for carrying out a plasma process on a semiconductor substrate in a plasma processing chamber, comprising:
- performing plasma processing of the semiconductor substrate, the plasma process including a plurality of processing steps;
- receiving, over a time period, electromagnetic signals emitted by one or more residual compounds in the plasma processing chamber during plasma processing of the semiconductor substrate in the plasma processing chamber, the signals having corresponding wavelengths;
- processing the received electromagnetic signals to generate predictive signals from the received electromagnetic signals, wherein processing the received electromagnetic signals includes integrating and normalizing the electromagnetic signals over the time period;
- analyzing the predictive signals over the time period;
- predicting presence of fabrication defects on the semiconductor substrate based on the analyzing of the predictive signals over the time period, wherein predicting includes comparing the predictive signals to predefined thresholds for percentage changes between consecutively integrated intensities of the predictive signals;
- modifying a parameter of one processing step of the plurality of processing steps of the plasma process based on the results of the predicting presence of fabrication defects on the semiconductor substrate;
- and
- continuing to perform the processing step of the plasma process with the modified parameter.
5 more elements
A method for carrying out a plasma process on a semiconductor wafer in a plasma processing chamber, comprising:
- performing plasma processing of the wafer;
- receiving, over a time period, a plurality of electromagnetic signals emitted by one or more residual compounds in the plasma processing chamber during plasma processing of the semiconductor wafer in the plasma processing chamber, the plurality signals having corresponding wavelengths;
- analyzing the plurality of received electromagnetic signals by integrating and normalizing the electromagnetic signals over the time period, including:
- grouping the plurality of electromagnetic signals into groups based on their corresponding wavelengths;
- and
- generating a plurality of predictive data, wherein the predictive data includes one or more of peak intensities, duration, intensity patterns, or correlation to other wavelengths;
- predicting presence of the one or more residual compounds in the plasma processing chamber based on the analyzing of the received electromagnetic signals by comparing the predictive data to predefined thresholds for percentage changes between consecutively integrated intensities of the predictive data;
- stopping the plasma process based on the results of the predicting presence of the one or more residual compounds in the plasma processing chamber;
- and
- cleaning the plasma processing chamber after the stopping the plasma process has occurred to remove the one or more residual compounds from the plasma processing chamber.
7 more elements
A method for carrying out a plasma process on a semiconductor wafer in a plasma processing chamber, comprising:
- performing plasma processing of the wafer using a flow of one or more active gases, the flow having a rate of flow;
- receiving at an optical emission spectrometer through a window in the plasma processing chamber, over a period of time, electromagnetic signals emitted by one or more residual compounds in the plasma processing chamber during plasma processing of the semiconductor wafer in the plasma processing chamber, the signals having corresponding wavelengths;
- analyzing the received electromagnetic signals by integrating and normalizing the signals over the time period, and predicting presence of fabrication defects based on the analyzing, wherein predicting includes comparing the integrated and normalized signals to predefined thresholds for percentage changes between consecutively integrated intensities of the signals;
- generating one or more control signals based on the analyzing of the received electromagnetic signals, wherein the control signals are configured to adjust the rate of flow of the one or more active gases;
- maintaining the flow of the one or more active gases into the plasma processing chamber at an alternative rate based on the generated one or more control signals to mitigate a risk of the semiconductor wafer incurring fabrication defects;
- and
- adjusting the flow rate of the active gases in real-time based on continuous monitoring and analysis of the received electromagnetic signals.
4 more elements
Dependencies are inferred from the claim text.