Operation monitoring method for treatment apparatus

• US 7,054,786 B2
• Filed: 07/03/2001
• Issued: 05/30/2006
• Est. Priority Date: 07/04/2000
• Status: Expired due to Term

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Sakano, Shinji, Sendoda, Tsuyoshi
• Primary Examiner(s): Assouad, Patrick J.
• Application Number:
  US10/332,011
• Publication Number:
  US 20040254761A1
• Time in Patent Office: 1,792 Days
• Field of Search: 702/183, 702/179, 702/181, 702/182, 702/187, 702/185, 700/121, 700/108, 700/109, 700/110
• US Class Current: 702/183
• CPC Class Codes: H01J 37/32935 Monitoring and controlling tubes by information coming from the object and/or discharge
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: H01L 22/20 Sequence of activities consisting of a plurality of measurements, corrections, marking or sorting steps

Abstract

In an operation monitoring method according to the present invention, operation data of a plasma processing system (1) are detected for every wafer (W) by means of a plurality of detectors, and a principal component analysis using the operation data is carried out by means of a controller (10). An operation state of the plasma processing system (1) is evaluated by using the results of the principal component analysis.

Claims

1. An operation monitoring method for monitoring an operation of a processing system by utilizing a plurality of detected values as operation data, the detected values being detected for every object to be processed by means of a plurality of detectors provided in the processing system, the method comprising the steps of:

obtaining previously a plurality of operation data with respect to a plurality of objects to be processed as references;

carrying out a principal component analysis using the operation data;

dividing the operation data into relatively high contribution principal components and low contribution principal components;

deriving a residual matrix of operation data belonging to the low contribution principal components; and

evaluating an operation state of the processing system on the basis of a first and a second principal component score and a residual score obtained by the residual matrix.

2. An operation monitoring method as set forth in claim 1, wherein a variance value of the first principal component score is used for determining a timing of stopping the operation.

3. An operation monitoring method as set forth in claim 1, wherein the residual matrix is derived from a higher-order principal component than the second principal component.

4. A processing system evaluating method for evaluating a difference in characteristics between a plurality of processing systems by utilizing a plurality of detected values as operation data, the detected values being detected for every object to be processed by means of a plurality of detectors provided in the processing systems, the method comprising the steps of:

obtaining first operation data for each of the objects to be processed by using a reference processing system;

carrying out a principal component analysis using the first operation data to derive a first residual matrix;

obtaining second operation data for each of the objects to be processed by using a comparative processing system to be compared with the reference processing system;

applying the second operation data to results of the principal component analysis to derive a second residual matrix; and

comparing the first residual matrix based on the first operation data with the second residual matrix based on the second operation data to evaluate a difference in performance between the processing systems.

5. A processing system evaluating method as set forth in claim 4, wherein the comparison of the first and second residual matrixes with each other is carried out by using residual scores.

6. A processing system monitoring method for measuring a plurality of electrical data of a high frequency source varying in accordance with a state in a processing system, by means of a measuring device, when a high frequency power is applied to an electrode in a processing vessel from the high frequency source for processing an object with plasma in the processing system, and for carrying out a multivariate analysis using the measured electrical data to detect a power application state of the high frequency source, the method comprising the steps of:

measuring the electrical data as reference data when the power application state of the high frequency source is stabilized in accordance with the state in the processing vessel in a reference processing system;

carrying out a multivariate analysis for reference using the obtained reference data;

measuring successively the electrical data as comparative data in a comparative processing system to be monitored, after the system is started;

carrying out a multivariate analysis for comparison using the obtained comparative data and

comparing results of the multivariate analysis for comparison with a result of the multivariate analysis for reference to determine, on the basis of a difference therebetween, whether the power application state of the high frequency source in the comparative processing system reaches a stable condition in accordance with the state in the processing vessel.

7. An operation monitoring method as set forth in claim 6, wherein at least voltage, current, impedance and phase angle of a fundamental wave and higher harmonic waves are used as the electrical data.

8. An operation monitoring method as set forth in claim 6, wherein the multivariate analysis is a principal component analysis.

9. An operation monitoring method as set forth in claim 8, wherein a residual score is used as the result of the principal component analysis.

10. An operation monitoring method as set forth in claim 9, wherein processing conditions and/or operating conditions in the processing system are determined on the basis of a result of comparison of the residual scores with each other.

11. An abnormality detecting method for detecting an abnormality of a processing system by measuring a plurality of electrical data of a high frequency source varying in accordance with a state in the processing system, by means of a measuring device, when a high frequency power is applied to an electrode in a processing vessel from the high frequency source for processing an object with plasma in the processing system, and by carrying out a multivariate analysis using the measured electrical data to detect a power application state of the high frequency source, the method comprising the steps of:

measuring the electrical data as reference data when the power application state of the high frequency source is stabilized in accordance with the state in the processing vessel in a normal reference processing system;

carrying out a multivariate analysis for reference using the obtained reference data;

measuring the electrical data as comparative data in a comparative processing system, the abnormality of which is to be detected;

carrying out a multivariate analysis for comparison using the obtained comparative data; and

comparing a result of the multivariate analysis for comparison with a result of the multivariate analysis for reference to detect the abnormality of the comparative processing system on the basis of a difference therebetween.

12. An abnormality detecting method as set forth in claim 11, wherein at least voltage, current, impedance and phase angle of a fundamental wave and higher harmonic waves are used as the electrical data.

13. An abnormality detecting method as set forth in claim 11, wherein the multivariate analysis is a principal component analysis.

14. An abnormality detecting method as set forth in claim 13, wherein a residual score is used as the result of the principal component analysis.

15. An abnormality detecting method as set forth in claim 13, wherein a cause of abnormality of the processing system is distinguished on the basis of components of a residual matrix obtained by the principal component analysis.

16. A processing system control unit for monitoring an operation of a processing system by utilizing a plurality of detected values as operation data, the detected values being detected for every object to be processed by means of a plurality of detectors provided in the processing system, the control unit executing a procedure comprising the steps of:

obtaining previously a plurality of operation data with respect to a plurality of objects to be processed as references;

carrying out a principal component analysis using the operation data;

dividing the operation data into relatively high contribution principal components and low contribution principal components;

deriving a residual matrix of operation data belonging to the low contribution principal components; and

evaluating an operation state of the processing system on the basis of a first and a second principal component score and a residual score obtained by the residual matrix.

17. A processing system control unit as set forth in claim 16, wherein a variance value of the first principal component score is used for determining a timing of stopping the operation.

18. A processing system control unit as set forth in claim 16, wherein the residual matrix is derived from a higher-order principal component than the second principal component.

19. A processing system control unit for evaluating a difference in characteristics between a plurality of processing systems by utilizing a plurality of detected values as operation data, the detected values being detected for every object to be processed by means of a plurality of detectors provided in the processing systems, the control unit executing a procedure comprising the steps of:

obtaining first operation data for each of the objects to be processed by using a reference processing system;

carrying out a principal component analysis using the first operation data to derive a first residual matrix;

obtaining second operation data for each of the objects to be processed by using a comparative processing system to be compared with the reference processing system;

applying the second operation data to results of the principal component analysis to derive a second residual matrix; and

comparing the first residual matrix based on the first operation data with the second residual matrix based on the second operation data to evaluate a difference in performance between the processing systems.

20. A processing system control unit as set forth in claim 19, wherein the comparison of the first and second residual matrixes with each other is carried out by using residual scores.

21. A processing system control unit for measuring a plurality of electrical data of a high frequency source varying in accordance with a state in a processing system, by means of a measuring devise, when a high frequency power is applied to an electrode in a processing vessel from the high frequency source for processing an object with plasma in the processing system, and for carrying out a multivariate analysis using the measured electrical data to detect a power application state of the high frequency source, the control unit executing a procedure comprising the steps of:

measuring the electrical data as reference data when the power application state of the high frequency source is stabilized in accordance with the state in the processing vessel in a reference processing system;

carrying out a multivariate analysis for reference using the obtained reference data;

measuring successively the electrical data as comparative data in a comparative processing system to be monitored, after the system is started;

carrying out a multivariate analysis for the comparison using the obtained comparative data; and

comparing results of the multivariate analysis for comparison with a result of the multivariate analysis for reference to determine, on the basis of a difference therebetween, whether the power application state of the high frequency source in the comparative processing system reaches a stable condition in accordance with the state in the processing vessel.

22. A processing system control unit as set forth in claim 21, wherein at least voltage, current, impedance and phase angle of a fundamental wave and higher harmonic waves are used as the electrical data.

23. A processing system control unit as set forth in claim 21, wherein the multivariate analysis is a principal component analysis.

24. A processing system control unit as set forth in claim 23, wherein a residual score is used as the result of the principal component analysis.

25. A processing system control unit as set forth in claim 24, wherein processing conditions and/or operating conditions in the processing system are determined on the basis of a result of comparison of the residual scores with each other.

26. A processing system control unit for detecting an abnormality of a processing system by measuring a plurality of electrical data of a high frequency source varying in accordance with a state in the processing system, by means of a measuring device, when a high frequency power is applied to an electrode in a processing vessel from the high frequency source for processing an object with plasma in the processing system, and by carrying out a multivariate analysis using the measured electrical data to detect a power application state of the high frequency source, the control unit executing a procedure comprising the steps of:

measuring the electrical data as reference data when the power application state of the high frequency source is stabilized in accordance with the state in the processing vessel in a normal reference processing system;

carrying out a multivariate analysis for reference using the obtained reference data;

measuring the electrical data as comparative data in a comparative processing system, the abnormality of which is to be detected;

carrying out a multivariate analysis for comparison using the obtained comparative data; and

comparing a result of the multivariate analysis for comparison with a result of the multivariate analysis for reference to detect the abnormality of the comparative processing system on the basis of a difference therebetween.

27. A processing system control unit as set forth in claim 26, wherein at least voltage, current, impedance and phase angle of a fundamental wave and higher harmonic waves are used as the electrical data.

28. A processing system control unit as set forth in claim 26, wherein the multivariate analysis is a principal component analysis.

29. A processing system control unit as set forth in claim 28, wherein a residual score is used as the result of the principal component analysis.

30. A processing system control unit as set forth in claim 28, wherein a cause of abnormality of the processing system is distinguished on the basis of components of a residual matrix obtained by the principal component analysis.