Method and apparatus for fault detection and control

• US 6,192,287 B1
• Filed: 09/22/1998
• Issued: 02/20/2001
• Est. Priority Date: 09/23/1997
• Status: Expired due to Term

• Current Assignee: MKS Instruments Incorporated
• Original Assignee: On-Line Technologies Inc.
• Inventors: Nelson, Chad M., Spartz, Martin L., Solomon, Peter R., Rosenthal, Peter A.
• Primary Examiner(s): Sheikh, Ayaz R.
• Assistant Examiner(s): Backer, Firmin
• Application Number:
  US09/158,380
• Time in Patent Office: 882 Days
• Field of Search: 700/110, 700/121, 700/266, 702/35, 702/28, 702/27, 324/537, 324/765, 382/149, 382/232, 714/724
• US Class Current: 700/110
• CPC Class Codes: H01J 37/32935 Monitoring and controlling tubes by information coming from the object and/or discharge
• CPC Class Codes: H01L 22/20 Sequence of activities consisting of a plurality of measurements, corrections, marking or sorting steps

Abstract

A fault detection and classification system for wafer etching, tool cleaning, and other fabrication processes employs exhaust gas composition data from a Fourier transform infrared spectrometer in addition to machine-state and other process-state data. Process control may be initiated based upon the classification of a fault.

Claims

1. A method for detection of faults occurring in a tool processing chamber in which a gaseous substance is produced, comprising the steps:

providing a tool having at least one processing chamber, and control means for varying processing conditions within said one chamber;

sensor means operatively connected to said tool for receiving data from a gaseous substance produced in said one chamber; and

electronic data processing means operatively connected to said sensor means, said data processing means and said sensor means being programmed and constructed, respectively, for determining compositional properties of gaseous substances from data received by said sensor means, said data processing means also being programmed for developing a characteristic gas composition profile for said gaseous substance based upon said compositional properties, and for comparing different said profiles with one another;

establishing nominal processing conditions in said one chamber of said tool;

effecting, in each of a multiplicity of preliminary runs, processing in said one chamber under said nominal processing conditions for the purpose of producing a result that satisfies established criteria, a gaseous substance being produced in said one chamber during each of said preliminary runs;

evaluating the result of each of said preliminary runs so as to identify each result that satisfies said established criteria, and thereby to identify each satisfactory preliminary run;

developing a gas composition profile for said gaseous substance produced during each of said satisfactory runs, and storing the resulting satisfactory composition profiles in said data processing means;

carrying out at least one more of said runs in said one chamber under said nominal processing conditions to produce a comparison gaseous substance;

developing a comparison gas composition profile for said comparison substance; and

comparing said comparison gas composition profile with said satisfactory gas composition profiles to determine if said comparison profile conforms to said satisfactory profiles, and thereby to determine if said one more run constitutes a satisfactory run or a faulty run depending, respectively, upon whether or not such conformity is produced.

2. The method of claim 1 wherein said sensor means comprises an optical sensor.

3. The method of claim 2 wherein said sensor means and data processing means perform absorption spectroscopy.

4. The method of claim 3 wherein said spectroscopy is carried out in the infrared spectral region.

5. The method of claim 4 wherein said sensor means is an FTIR spectrometer.

6. The method of claim 1 wherein said gaseous substance is exhausted from said one chamber, and wherein said sensor means is operatively connected for receiving said data from said exhausted gaseous substance.

7. The method of claim 6 wherein said sensor means comprises an optical sensor.

8. The method of claim 7 wherein said sensor means and data processing means perform absorption spectroscopy.

9. The method of claim 8 wherein said spectroscopy is carried out in the infrared spectral region.

10. The method of claim 9 wherein said sensor means is an FTIR spectrometer.

11. The method of claim 1 wherein said sensor means comprises a filter-based, non-dispersive, infrared absorption spectrometer.

12. The method of claim 1 wherein said sensor means comprise a quadrapole mass spectrometer.

13. The method of claim 1 wherein each unsatisfactory preliminary run, which fails to conform to said established criteria, is also identified in said step of evaluating;

wherein a gas composition profile for said gaseous substance produced during each of said unsatisfactory runs is developed and stored, as a resulting unsatisfactory composition profile, in said data processing means; and

wherein said comparison gas composition profile is optionally compared with said unsatisfactory composition profiles in said step of comparing.

14. The method of claim 13 wherein said comparison composition is compared with said unsatisfactory comparison profiles only if said one more run constitutes a faulty run.

15. The method of claim 1 wherein said tool additionally includes tool state-determining means operatively connected for determining at least one tool state parameter affecting processing in said one chamber, and process state-determining means for determining at least one process state parameter in addition to said compositional properties of said gaseous substance;

wherein said at least one tool state parameter determined and said at least one process state parameter determined for each of said preliminary runs and said one more run are stored in said data processing means;

wherein said data processing means is programmed for comparing said stored parameters; and

wherein said stored parameters for said one more run are compared with said stored parameters for said preliminary runs in said step of comparing.

16. The method of claim 15 wherein said data processing means is programmed to effect a multivariate correlation technique in said step of comparing.

17. The method of claim 14 wherein said tool additionally includes tool state-determining means operatively connected for determining at least one tool state parameter affecting processing in said one chamber, and process state-determining means for determining at least one process state parameter in addition to said compositional properties of said gaseous substance;

wherein said at least one tool state parameter determined and said at least one process state parameter determined for each of said preliminary runs and said one more run are stored in said data processing means;

wherein said data processing means is programmed for comparing said stored parameters; and

wherein said stored parameters for said one more run are compared with said stored parameters for said preliminary runs in said step of comparing, at least for the purpose of classifying said faulty run as to cause.

18. The method of claim 17 wherein said data processing means is programmed to effect a multivariate correlation technique in said step of comparing and for classifying said faulty run.

19. The method of claim 17 wherein said data processing means is programmed for automatically initiating action to effect correction of the cause of said faulty run.

20. The method of claim 14 wherein subsequent runs are effected after said preliminary runs and before said one more run;

wherein said method automatically carries out said subsequent and one more runs in continuous sequence; and

wherein said method is automatically terminated after said one more run.

21. The method of claim 1 wherein processing of substantially identical semiconductor devices is carried out in said runs, said established criteria relating to the properties of said devices.

22. The method of claim 21 wherein said processing is carried out for etching of the surfaces of said semiconductor devices, and wherein said evaluating step entails the analysis of the vapor phase etch products for the determination of etch rate and depth.

23. The method of claim 21 wherein said processing is carried out for deposition of at least one layer comprising said semiconductor devices, and wherein said evaluating step entails the analysis of layer properties.

24. The method of claim 1 wherein processing is carried out in said runs to effect cleaning of elements associated with said processing chamber, said established criteria relating to the condition of such elements.

25. Apparatus for detection of faults occurring in a tool processing chamber in which a gaseous substance is produced, comprising:

sensor means constructed for operative connection to a tool having at least one processing chamber, for receiving data from a gaseous substance produced in the chamber; and

electronic data processing means operatively connected to said sensor means, said data processing means and said sensor means being programmed and constructed, respectively, for determining compositional properties of gaseous substances from data received by said sensor means, said data processing means also being programmed for storing data, for developing characteristic gas composition profiles for gaseous substances based upon their compositional properties, and for comparing different such profiles with one another;

whereby, with nominal processing conditions established in the chamber of the tool;

processing in the tool chamber may be effected, in each of a multiplicity of preliminary runs, for the purpose of producing a result that satisfies established criteria;

the result of each preliminary run may be evaluated so as to identify each result that satisfies the established criteria, and to thereby identify each satisfactory preliminary run;

a gas composition profile may be developed for the gaseous substance produced during each satisfactory run, and the resulting satisfactory composition profiles may be stored in said data processing means;

at least one more run may be carried out in the tool chamber, under the nominal processing conditions established, to produce a comparison gaseous substance;

a comparison gas composition profile may be developed for the comparison substance; and

the comparison gas composition profile may be compared with the satisfactory gas composition profiles to determine if the comparison profile conforms to the satisfactory profiles, thereby to determine if the one more run constitutes a satisfactory run or a faulty run depending, respectively, upon whether or not such conformity is produced.

26. The apparatus of claim 25 wherein said sensor means comprises an optical sensor.

27. The apparatus of claim 26 wherein said sensor means and said data processing means are constructed and programmed, respectively, to perform absorption spectroscopy.

28. The apparatus of claim 25 wherein said sensor means comprises a Fourier transform infrared spectrometer.

29. The apparatus of claim 25 wherein said sensor means comprises a filter-based, non-dispersive, infrared absorption spectrometer.

30. The apparatus of claim 25 wherein said sensor means comprises a quadrapole mass spectrometer.

31. The apparatus of claim 25 wherein said data processing means is so programmed that:

each unsatisfactory preliminary run, which fails to conform to the established criteria, is also identified in the step of evaluating;

a gas composition profile for the gaseous substance produced during each of the unsatisfactory runs is developed and stored, as a resulting unsatisfactory composition profile, in said data processing means; and

the comparison gas composition profile is optionally compared with the unsatisfactory composition profiles in the step of comparing.

32. The apparatus of claim 31 wherein the comparison composition is compared with the unsatisfactory comparison profiles only if the one more run is determined to constitute a faulty run.

33. The apparatus of claim 25 wherein said data processing means is programmed to store at least one tool state parameter and at least one process state parameter, in addition to the compositional properties of the gaseous substance, for each of the preliminary runs and the one more run, and for comparing the stored parameters for the one more run with the stored parameters for the preliminary runs, in the step of comparing.

34. The apparatus of claim 32 wherein said data processing means is programmed to store at least one tool state parameter and at least one process state parameter, in addition to the compositional properties of the gaseous substance, for each of the preliminary runs and the one more run, and for comparing the stored parameters for the one more run with the stored parameters for the preliminary runs, in the step of comparing, at least for the purpose of classifying the faulty run as to cause.

35. The apparatus of claim 34 wherein said data processing means is programmed to effect a multivariate correlation technique in the step of comparing.

36. The apparatus of claim 34 wherein said data processing means is programmed for automatically initiating action to effect correction of the cause of the faulty run.

37. A processing system having fault-detecting capability, comprising:

a tool having at least one processing chamber, and control means for varying the processing conditions within said one chamber;

sensor means operatively connected to said tool for receiving data from a gaseous substance produced in said chamber; and

electronic data processing means operatively connected to said sensor means, said data processing means and said sensor means being programmed and constructed, respectively, for determining compositional properties of gaseous substances from data received by said sensor means, said data processing means also being programmed for storing data, for developing characteristic gas composition profiles for gaseous substances based upon their compositional properties, and for comparing different such profiles with one another;

whereby, with nominal processing conditions established in the chamber of the tool;

processing in said chamber of said tool may be effected, in each of a multiplicity of preliminary runs, for the purpose of producing a result that satisfies established criteria;

the result of each preliminary run may be evaluated so as to identify each result that satisfies the established criteria, and thereby to identify each satisfactory preliminary run;

a gas composition profile may be developed for the gaseous substance produced during each satisfactory run, and the resulting satisfactory composition profiles may be stored in said data processing means;

at least one more run may be carried out in said tool chamber, under the nominal processing conditions established, to produce a comparison gaseous substance;

a comparison gas composition profile may be developed for the comparison substance; and

the comparison gas composition profile may be compared with the satisfactory gas composition profiles to determine if the comparison profile conforms to the satisfactory profiles, thereby to determine if the one more run constitutes a satisfactory run or a faulty run depending, respectively, upon whether or not such conformity is produced.

38. The system of claim 37 wherein said sensor means comprises a Fourier transform infrared spectrometer.

39. The system of claim 37 wherein said sensor means comprises a filter-based, non-dispersive, infrared absorption spectrometer.

40. The system of claim 37 wherein said sensor means comprises a quadrapole mass spectrometer.

41. The system of claim 37 wherein said data processing means is so programmed that:

each unsatisfactory preliminary run, which fails to conform to the established criteria, is also identified in the step of evaluating;

a gas composition profile for the gaseous substance produced during each of the unsatisfactory runs is developed and stored, as a resulting unsatisfactory composition profile, in said data processing means; and

the comparison gas composition profile is optionally compared with the unsatisfactory composition profiles in the step of comparing.

42. The system of claim 41 wherein said tool additionally includes tool state-determining means operatively connected for determining at least one tool state parameter affecting processing in said one chamber, and process state-determining means for determining at least one process state parameter in addition to gas composition properties;

and wherein said data processing means is programmed to store at least one tool state parameter and at least the one additional process state parameter for each of the preliminary runs and the one more run, and for comparing the stored parameters for the one more run with the stored parameters for the preliminary runs, in the step of comparing.

43. The system of claim 37 wherein said data processing means is so programmed that:

each unsatisfactory preliminary run, which fails to conform to the established criteria, is also identified in the step of evaluating;

a gas composition profile for the gaseous substance produced during each of the unsatisfactory runs is developed and stored, as a resulting unsatisfactory composition profile, in said data processing means; and

the comparison gas composition profile is optionally compared with the unsatisfactory composition profiles in the step of comparing, the comparison composition profile being compared with the unsatisfactory comparison profiles only if the one more run is determined to constitute a faulty run.

44. The system of claim 43 wherein said tool additionally includes tool state-determining means operatively connected for determining at least one tool state parameter affecting processing in said one chamber, and process state-determining means for determining at least one process state parameter in addition to gas composition properties;

and wherein said data processing means is programmed to store at least one tool state parameter and at least the one additional process state parameter for each of the preliminary runs and the one more run, and for comparing the stored parameters for the one more run with the stored parameters for the preliminary runs, in the step of comparing, at least for the purpose of classifying the faulty run as to cause.

45. The system of claim 44 wherein said data processing means is programmed for automatically initiating action to effect correction of the cause of the faulty run.

46. The system of claim 42 wherein said tool is constructed for the fabrication of semiconductor devices.

47. The system of claim 46 wherein said tool has means for receiving gaseous substances exhausted from said one chamber, and wherein said sensor means is operatively connected for receiving data from a gaseous substance in said means for receiving.