Method and apparatus for monitoring plasma processing operations

• US 6,169,933 B1
• Filed: 04/23/1998
• Issued: 01/02/2001
• Est. Priority Date: 04/23/1998
• Status: Expired due to Fees

• Current Assignee: Sandia Corporation (Martin Marietta Corporation)
• Original Assignee: Sandia Corporation (Martin Marietta Corporation)
• Inventors: Ward, Pamela Peardon Denise, Smith, Michael Lane Jr., Stevenson, Joel OʼDon
• Primary Examiner(s): Sheikh, Ayaz R.
• Assistant Examiner(s): VO, TIM T
• Application Number:
  US09/065,247
• Time in Patent Office: 985 Days
• Field of Search: 700/121, 700/123, 228/123.1, 228/179.1, 228/180.5, 438/31, 438/513, 438/710, 505/300, 385/14, 134/1, 716/1, 716/19
• US Class Current: 700/121
• CPC Class Codes: G01J 2003/2866 Markers; Calibrating of scan
• CPC Class Codes: G01J 3/28 Investigating the spectrum using colour filters G01J3/51
• CPC Class Codes: G01J 3/443 Emission spectrometry

Abstract

The invention generally relates to various aspects of a plasma process, and more specifically the monitoring of such plasma processes. One aspect relates in at least some manner to calibrating or initializing a plasma monitoring assembly. This type of calibration may be used to address wavelength shifts, intensity shifts, or both associated with optical emissions data obtained on a plasma process. A calibration light may be directed at a window through which optical emissions data is being obtained to determine the effect, if any, that the inner surface of the window is having on the optical emissions data being obtained therethrough, the operation of the optical emissions data gathering device, or both. Another aspect relates in at least some manner to various types of evaluations which may be undertaken of a plasma process which was run, and more typically one which is currently being run, within the processing chamber. Plasma health evaluations and process identification through optical emissions analysis are included in this aspect. Yet another aspect associated with the present invention relates in at least some manner to the endpoint of a plasma process (e.g., plasma recipe, plasma clean, conditioning wafer operation) or discrete/discernible portion thereof (e.g., a plasma step of a multiple step plasma recipe). A final aspect associated with the present invention relates to how one or more of the above-noted aspects may be implemented into a semiconductor fabrication facility, such as the distribution of wafers to a wafer production system.

Claims

1. A method for controlling a wafer production system, comprising the steps of:

distributing at least one wafer to each of first and second processing chambers;

processing said at least one wafer in the respective said processing chamber after each execution of said distributing step associated with the respective said processing chamber, said processing step comprising the steps of;

running a plasma process on said at least one wafer in the respective said processing chamber;

monitoring a plasma in the respective said processing chamber used by said running step; and

removing said at least one wafer from the respective said processing chamber;

repeating said distributing step a plurality of times for each of said first and second processing chambers after said removing step for said first and second processing chambers, respectively; and

suspending at least one execution of said distributing step in relation to any of said first and second processing chambers if a first said monitoring step for a first said running step in the respective said processing chamber identifies a first condition, said first condition being selected from the group consisting of a dirty chamber condition which is when an interior of the respective said processing chamber has been adversely affected by previous executions of said processing step in the respective said processing chamber to the point where it is adversely impacting a performance of the respective said processing chamber to an undesired degree, a known error condition which is when said first said running step has proceeded other than in accordance with at least one standard associated with said running step in the respective said processing chamber, an unknown condition which is when said first said monitoring step identifies a condition which said first said monitoring step has not previously encountered in any prior execution of said processing step in the respective said processing chamber, and any combination of the foregoing.

2. A method, as claimed in claim 1, wherein:

said monitoring step comprises monitoring optical emissions of said plasma which includes at least wavelengths from about 250 nanometers to about 1,000 nanometers, inclusive, at least at every 1 nanometer.

3. A method, as claimed in claim 1, wherein:

said monitoring step comprises evaluating a condition of said plasma in the respective said processing chamber, wherein said condition is a cumulative result of all parameters having an effect on said plasma in the respective said processing chamber.

4. A method, as claimed in claim 1, wherein:

said suspending step is initiated in relation to the respective said processing chamber immediately after said first said monitoring step identifies said first condition.

5. A method, as claimed in claim 1, wherein:

said suspending step is initiated in relation to the respective said processing chamber after at least one more execution of said distributing step after said first said monitoring step identifies said first condition.

6. A method, as claimed in claim 1, wherein:

said suspending step in relation to said first processing chamber is initiated immediately after said first said monitoring step in said first processing chamber identifies said first condition.

7. A method, as claimed in claim 1, wherein:

said suspending step in relation said first processing chamber is initiated only after a predetermined number of said monitoring steps associated with said first processing chamber each identify said first condition.

8. A method, as claimed in claim 1, wherein:

when said suspending step is based upon said first condition being a first said dirty chamber condition in one of said first and second processing chambers, said method further comprises the step of cleaning said one of said first and second processing chambers during the associated said suspending step.

9. A method, as claimed in claim 1, wherein:

when said suspending step is based upon said first condition being a first said known error condition in one of said first and second processing chambers, said method further comprises the step of addressing said first said known error condition in relation to said one of said first and second processing chambers during said running step in which said first condition was encountered.

10. A method, as claimed in claim 1, wherein:

when said suspending step is based upon said first condition being a first said unknown condition in one of said first and second processing chambers, said method further comprises the step of evaluating data from said first said monitoring step associated with said one of said first and second processing chambers, said evaluating step being executed during said suspending step for said one of said first and second processing chambers.

11. A method, as claimed in claim 8, further comprising the step of:

re-initiating said distributing step for said one of said first and second processing chambers after said cleaning step, said re-initiating step thereby terminating said suspending step.

12. A method for controlling a wafer production system, comprising the steps of:

distributing at least one wafer to each of first, second, and third processing chambers;

processing said at least one wafer in the respective said processing chamber after each execution of said distributing step, said processing step comprising the steps of;

running a plasma process on said at least one wafer in the respective said processing chamber;

monitoring a plasma in the respective said processing chamber used by said running step; and

removing said at least one wafer from said processing chamber;

repeating said distributing step for said first, second, and third processing chambers a plurality of times after each said removing step associated with said first, second, and third processing chambers, respectively;

using a first distribution sequence for said distributing step, said first distribution sequence being said distributing step is executed first for said first processing chamber, second for said second processing chamber, and third for said third processing chamber;

discontinuing said first distribution sequence if said monitoring step from at least one of said processing steps in said first processing chamber identifies a first condition; and

using a second distribution sequence after any execution of said discontinuing step, said second distribution sequence being different from said first distribution sequence.

13. A method, as claimed in claim 12, wherein:

said monitoring step comprises monitoring optical emissions of said plasma in the respective said processing chamber which includes at least wavelengths from about 250 nanometers to about 1,000 nanometers, inclusive, at least at every 1 nanometer.

14. A method, as claimed in claim 12, wherein:

said monitoring step comprises evaluating a condition of said plasma in the respective said processing chamber, wherein said condition is a cumulative result of all parameters having an effect on said plasma in the respective said processing chamber.

15. A method, as claimed in claim 12, wherein:

said first condition is selected from the group consisting of a dirty chamber condition which is when an interior of said first processing chamber has been adversely affected by previous executions of said processing step in said first processing chamber to the point where it is adversely impacting a performance of said first processing chamber to an undesired degree, a known error condition which is when said running step of said at least one processing step has proceeded other than in accordance with at least one standard associated with said running step of said at least one processing step for said first processing chamber, an unknown condition which is when said monitoring step associated with said at least one processing step identifies a condition which said monitoring step has not previously encountered in any prior execution of said processing step in said first processing chamber, and any combination of the foregoing, wherein said using said second distribution sequence step comprises suspending at least one execution of said distributing step in relation to said first processing chamber after said monitoring step from said at least one processing step in said first processing chamber identifies said first condition.

16. A method, as claimed in claim 12, wherein:

said first condition is a dirty chamber condition which is when an interior of said first processing chamber has been adversely affected by previous executions of said processing step in said first processing chamber to the point where it is adversely impacting a performance of said first processing chamber to an undesired degree, wherein said method further comprises the step of scheduling a cleaning date for said first processing chamber for conducting a cleaning operation after said first condition is identified in said first processing chamber.

17. A method, as claimed in claim 15, wherein:

said suspending step is initiated immediately after any said monitoring step of a single said processing step in said first processing chamber identifies said first condition.

18. A method, as claimed in claim 15, wherein:

said suspending step is initiated only after said monitoring step in a predetermined number of said processing steps in said first processing chamber each identify said first condition.

19. A method, as claimed in claim 15, wherein:

when said suspending step is based upon said first condition being a first said dirty chamber condition in said first processing chamber, said method further comprises the step of cleaning said first processing chamber during said suspending step.

20. A method, as claimed in claim 15, wherein:

when said suspending step is based upon said first condition being a first said known error condition in said first processing chamber, said method further comprises the step of addressing said first said known error condition during said running step in said first processing chamber where said first condition was encountered.

21. A method, as claimed in claim 15, wherein:

when said suspending step is based upon said first condition being a first said unknown condition in said first processing chamber, said method further comprises the step of evaluating data from said monitoring step associated with said running step in said first processing chamber where said first condition was encountered, said evaluating step being executed during said suspending step.

22. A method, as claimed in claim 16, wherein:

said using a second distribution sequence comprises giving said first processing chamber a priority in relation to said distributing step until said cleaning date, wherein said giving said first processing chamber a priority step means maximizing a number of said processing steps for said first processing chamber before said cleaning date.

23. A method, as claimed in claim 19, further comprising the step of:

re-initiating said distributing step for said first processing chamber after said cleaning step using said first distribution sequence instead of said second distribution sequence, said re-initiating step thereby terminating said suspending step.

24. A method for controlling a wafer production system, comprising the steps of:

distributing at least one wafer to each of first and second processing chambers;

processing said at least one wafer in the respective said processing chamber after each execution of said distributing step associated with the respective said processing chamber, said processing step comprising the steps of;

running a plasma process on said at least one wafer in the respective said processing chamber;

monitoring a time for completing said plasma process in the respective said processing chamber; and

removing said at least one wafer from the respective said processing chamber;

repeating said distributing step a plurality of times for each of said first and second processing chambers after said removing step for said first and second processing chambers, respectively; and

using a first sequence for said distributing step which is based on said monitoring step for at least one of said processing step of said first and second chambers, respectively.

25. A method, as claimed in claim 24, wherein:

said plasma process comprises at least one plasma step, wherein said monitoring step comprises identifying an endpoint of each said plasma step of said plasma process, wherein said endpoint for each said plasma step is when said plasma step has achieved a predetermined result on said wafer.

26. A method, as claimed in claim 24, wherein:

said using a first sequence step comprises giving a priority to one of said first and second processing chambers having a smaller said time from said monitoring step than the other of said first and second processing chambers.