Method and apparatus for monitoring plasma processing operations

• US 6,275,740 B1
• Filed: 04/23/1998
• Issued: 08/14/2001
• 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): Grant, William
• Assistant Examiner(s): Bahta, Kidest
• Application Number:
  US09/065,274
• Time in Patent Office: 1,209 Days
• Field of Search: 700/121, 700/123, 700/33, 700/18, 702/84, 702/188, 204/298.32, 216/59, 216/60, 438/9, 156/345
• US Class Current: 700/108
• 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 running a plasma process on product in a processing chamber using a computer-readable storage medium, said computer-readable storage medium comprising a plurality of data entries, wherein a first said data entry comprises a plurality of optical emissions data segments of plasma from a first said plasma process previously run on product in said processing chamber which had proceeded in accordance with a first standard, wherein a second said data entry comprises a plurality of optical emissions data segments of plasma from a second said plasma process previously run on product in said processing chamber which had proceeded in accordance with a second standard, said first said plasma process being a different type than said second said plasma process, said method comprising the steps of:

loading a quantity of product into said processing chamber;

running a third said plasma process on said product in said processing chamber;

obtaining optical emissions data on said third said plasma process; and

determining if said third said plasma process is a same type as one of said first and second said plasma processes, said determining step using said obtaining step, being executed during said running a third said plasma process step, and including comparing said optical emissions data from said third said plasma process with said optical emissions data segments of at least one of said first and second said data entries.

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

an identity of said first said plasma process and said second said plasma process is provided in said computer-readable storage medium in relation to said first and second said data entries, respectively.

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

said loading step comprises loading at least one wafer into said processing chamber.

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

said optical emissions data from said third said plasma process and each of said optical emissions segments of said first and second said data entries comprise each wavelengths from about 250 nanometers to about 1,000 nanometers, inclusive, at least at every 1 nanometer and which defines a first wavelength range.

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

said determining step comprises determining if said optical emissions data from a given point in time of said third said plasma process are within a predetermined tolerance of at least one of said optical emissions data segments from at least one of said first and second data entries, respectively.

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

said determining step comprises determining if a pattern of said optical emissions data from a given point in time of said third said plasma process is at least substantially a match with a pattern of at least one of said optical emission data segments from at least one of said first and second data entries, respectively.

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

said determining step comprises determining if said optical emissions data at a first time in said third said plasma process are within a predetermined tolerance of said optical emissions data segment which is also associated with said first time from at least one of said first and second data entries, respectively.

8. A method, as claimed in claim 4, wherein in relation to each of said first and second said data entries, said determining step comprises:

performing a first determining step comprising determining if said optical emissions data at a current time in said third said plasma process satisfies a first condition, said first condition being that said optical emissions data at said current time of said third said plasma process are within a predetermined tolerance of at least one of said optical emissions data segments from said data entry;

designating an earliest-in-time of said at least one of said optical emissions data segments as a current said optical emissions data segment if said performing a first determining step identifies said first condition;

terminating said performing a first determining step in relation to said data entry if said performing a first determining step fails to identify said first condition;

repeating a loop if said performing a first determining step identifies said first condition and until execution of an exiting step associated with said loop, said loop comprising the steps of;

increasing said current time by a first increment;

performing a second determining step comprising determining if said optical emissions data at said current time of said third said plasma process satisfies a second condition, said second condition being that said optical emissions data at said current time of said third said plasma process are within a predetermined tolerance of a next-in-time said optical emissions data segment following said current said optical emissions data segment;

performing a third determining step only if said performing a second determining step fails to identify said second condition, said performing a third determining step comprising determining if said optical emissions at said current time of said third said plasma process satisfy a third condition, said third condition being that said optical emissions at said current time of said third said plasma process are within a predetermined tolerance of said current said optical emissions data segment;

exiting said loop when at least one of fourth and fifth conditions exist, said fourth condition being if said performing a third determining step was executed and failed to identify said third condition, said fifth condition being if all of said optical emissions data from said third said plasma process step that has been made available for said determining step has been evaluated by said determining step; and

setting said next-in-time said optical emissions data segment equal to said current said optical emissions data segment only if said performing a second determining step identified said second condition.

9. A method, as claimed in claim 1, further comprising the step of:

displaying results of said determining step.

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

said third said plasma process comprises a plurality of plasma steps, said method further comprising the step of identifying each of said plurality of plasma steps using said determining step, said identifying step being executed during said running a third said plasma process step and using said obtaining step.

11. A method for running a plasma process on product within a processing chamber, said method comprising steps of:

loading a quantity of product into said processing chamber;

inputting a type of said plasma process to be run on said product within said processing chamber, said inputting step being to at least one controller associated with said processing chamber;

running a first said plasma process on said product within said processing chamber based upon said inputting step;

obtaining data relating to a plasma within said processing chamber during said running step;

identifying said type of said first said plasma process from said obtaining step; and

displaying said type of said first said plasma process from said identifying step and during said running step.

12. A method, as claimed in claim 11, wherein:

said loading step comprises loading at least one wafer into said processing chamber.

13. A method, as claimed in claim 11, wherein:

said obtaining step comprises obtaining current optical emissions of plasma within said processing chamber during said running step.

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

said current optical emissions include at least wavelengths from about 250 nanometers to about 1,000 nanometers, inclusive, at least at every 1 nanometer, and which defines a first wavelength range.

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

said identifying step uses a computer-readable storage medium system comprising at least one data entry, wherein a first said data entry comprises a plurality of data segments relating to a second said plasma process previously run on product in said processing chamber, wherein each said data segment comprises stored optical emissions of a plasma in said processing chamber during said second said plasma process, and wherein said obtaining step comprises obtaining current optical emissions of said plasma in said processing chamber during said running step.

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

said identifying step comprises determining if said current optical emissions are within a predetermined tolerance of said stored optical emissions of at least one of said data segments from said first data entry.

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

said identifying step comprises determining if a pattern of said current optical emissions is at least substantially a match with a pattern of said stored optical emissions of at least one of said data segments from said first data entry.

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

said identifying step comprises determining if said current optical emissions at a first time are within a predetermined tolerance of said stored optical emissions of said data segment of said first data entry which is also associated with said first time.

19. A method, as claimed in claim 15, wherein said identifying step comprises:

performing a first determining step comprising determining if said current optical emissions at a current time satisfy a first condition, said first condition being that said current optical emissions at said current time are within a predetermined tolerance of said stored optical emissions of at least one of said data segments from said first data entry;

designating an earliest-in-time of said at least one of said data segments as a current said data segment if said performing a first determining step identifies said first condition;

terminating said identifying step in relation to said first data entry if said performing a first determining step fails to identify said first condition;

repeating a loop if said performing a first determining step identifies said first condition and until execution of an exiting step associated with said loop, said loop comprising the steps of;

increasing said current time by a first increment;

performing a second determining step comprising determining if said current optical emissions at said current time satisfy a second condition, said second condition being that said current optical emissions at said current time are within a predetermined tolerance of said stored optical emissions of a next-in-time said data segment following said current said data segment;

performing a third determining step only if said performing a second determining step fails to identify said second condition, said performing a third determining step comprising determining if said current optical emissions at said current time satisfy a third condition, said third condition being that said current optical emissions at said current time are within a predetermined tolerance of said stored optical emissions of said current said data segment;

exiting said loop when at least one of fourth and fifth conditions exist, said fourth condition being if said performing a third determining step was executed and failed to identify said third condition, said fifth condition being if all of said current optical emissions from said running a third said plasma process step have been evaluated by said determining step;

setting said next-in-time said data segment equal to said current said data segment only if said performing a second determining step identified said second condition.

20. A method, as claimed in claim 11, wherein:

said first said plasma process comprises a plurality of plasma steps, said method further comprising the step of identifying each of said plurality of plasma steps using said identifying step.

21. A method, as claimed in claim 11, wherein:

said identifying step uses a computer-readable storage medium, wherein said computer-readable storage medium comprises a first data structure comprising a plurality of data entries, wherein a second said data entry comprises data relating to a second said plasma process previously run on product in said processing chamber which has proceeded in accordance with a second standard, wherein a third said data entry comprises data relating to a third said plasma process previously run on product in said processing chamber which has proceeded in accordance with a third standard, wherein said second said plasma process is of a second type and said third said plasma process is of a third type, and wherein said second and third types are different.

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

said inputting step comprises inputting said second type of said plasma process, wherein said identifying step comprises comparing said data from said obtaining step with said data in said first data structure of said computer-readable storage medium, and wherein said method further comprises the step of at least initially limiting said comparing step to only said data in said second data entry.

23. A method, as claimed in claim 11, further comprising the steps of:

providing instructions to an operator regarding a first type of said plasma process to be run on said product in said processing chamber; and

executing said inputting step after said providing instructions step, wherein said identifying step provides information as to whether said type from said inputting step is the same as said first type from said providing step to address potential operator error associated with said inputting step.

24. A plasma monitoring system for a plasma process run on product in a processing chamber, said system comprising:

a computer-readable storage medium comprising;

a first data structure comprising a first data entry, wherein data associated with a first said plasma process run on product in said processing chamber may be entered in said first data entry;

means for receiving data on a second said plasma process being run on product in said processing chamber during said second plasma process;

means for determining a type of said second said plasma process, said means for determining comprising said means for receiving, using data stored in said first data structure, and providing output before a termination of said second said plasma process.

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

said means for receiving comprises means for receiving data representative of optical emissions of plasma within said processing chamber during said second said plasma process.

26. A system, as claimed in claim 25, wherein:

said current optical emissions include at least wavelengths from about 250 nanometers to about 1,000 nanometers, inclusive, at least at every 1 nanometer and which defines a first wavelength range.

27. A system, as claimed in claim 24, wherein:

said first said data entry comprises a plurality of data segments relating to said first said plasma process run on product in said processing chamber, wherein each said data segment is available for storing data representative of optical emissions of a plasma in said processing chamber during said first said plasma process, and wherein said means for receiving comprises means for receiving data representative of current optical emissions of plasma within said processing chamber during said second said plasma process.

28. A system, as claimed in claim 27, wherein:

said means for determining comprises means for determining if said data representative of current optical emissions are within a predetermined tolerance of said data representative of optical emissions of at least one of said data segments from said first data entry.

29. A system, as claimed in claim 27, wherein:

said means for determining comprises means for determining if a pattern of said data representative of current optical emissions is at least substantially a match with a pattern of said data representative of optical emissions of at least one of said data segments from said first data entry.

30. A system, as claimed in claim 27, wherein:

said means for determining comprises means for determining if said data representative of current optical emissions at a first time are within a predetermined tolerance of said data representative of optical emissions of said data segment from said first data entry which is also associated with said first time.

31. A system, as claimed in claim 27, wherein said means for determining comprises:

first determining means comprising means for determining if said data representative of current optical emissions at a current time satisfies a first condition, said first condition being that said data representative of current optical emissions at said current time are within a predetermined tolerance of said data representative of optical emissions of at least one of said data segments from said first data entry;

means for designating an earliest-in-time of said at least one of said data segments as a current said data segment if said first determining means identifies said first condition;

means for deactivating said first determining means if said first determining means fails to identify said first condition;

means for repeating a loop if said first determining means identifies said first condition and until activation of a means for exiting associated with said loop, said loop comprising;

means for increasing said current time by a first increment;

second determining means for determining if said data representative of current optical emissions at said current time satisfies a second condition, said second condition being that said data representative of current optical emissions at said current time are within a predetermined tolerance of said data representative of optical emissions of a next-in-time said data segment following said current said data segment;

third determining means for determining if said data representative of current optical emissions at said current time satisfies a third condition, said third condition being that said data representative of current optical emissions at said current time are within a predetermined tolerance of said data representative of optical emissions from said current said data segment, said third determining means being activated only if said second determining means fails to identify said second condition;

means for exiting said loop when at least one of fourth and fifth conditions exist, said fourth condition being if said third determining means was activated and failed to identify said third condition, said fifth condition being if all of said current optical emissions from said second said plasma process have been evaluated by said means for determining;

means for setting said next-in-time said data segment equal to said current said data segment, said means for setting being activated only if said second determining means has identified said second condition.

32. A system, as claimed in claim 24, wherein:

said first said plasma process comprises a plurality of plasma steps, said system further comprising means for identifying each of said plurality of plasma steps using said means for determining.

33. A method for monitoring a plasma processing system comprising a processing chamber, a product storage device comprising a plurality of product, and a computer-readable storage medium, said computer-readable storage medium comprising a plasma recipe section, said plasma recipe section comprising a plurality of data entries, wherein a first said data entry comprises data relating to a first plasma recipe, wherein a second said data entry comprises data relating to a second plasma recipe, wherein said first plasma recipe is different from said second plasma recipe, and wherein a running a plasma process step comprises the steps of removing at least one product from said product storage device, loading said at least one product into said processing chamber, exposing said at least one product in said processing chamber to a plasma in accordance with one of said first and second plasma recipes, and removing said at least one product from said processing chamber after said exposing step, said method comprising the steps of:

executing a first said running step, wherein said exposing step of said executing a first said running step is associated only with said first plasma recipe;

monitoring at least one characteristic of said plasma during said executing a first said running step;

identifying that said executing a first said running step is associated only with said first plasma recipe by making both said first and second said data entries of said plasma recipe section of said computer-readable storage medium available for comparison with an output from said monitoring step;

executing a plurality of said running steps after said executing a first said running step, wherein said exposing step of each said executing plurality of running steps is in accordance only with said first plasma recipe; and

identifying that each of said running steps of said executing a plurality of said running steps is associated only with said first plasma recipe, said identifying step comprising at least initially limiting any comparison of said output of said monitoring step with said plasma recipe section of said computer-readable storage medium to only said first said data entry of said plasma recipe section.

34. A method, as claimed in claim 33, wherein:

said identifying step further comprises allowing any comparison of said output of said monitoring step with said plasma recipe section of said computer-readable storage medium to further include said second said data entry of said plasma recipe section for one of said running steps of said executing a plurality of running steps if said one of said running steps fails to correspond with said first said data entry.

35. A method, as claimed in claim 33, wherein:

said identifying step comprises always limiting any comparison of said output of said monitoring step with said plasma recipe section of said computer-readable storage medium to only said first said data entry of said plasma recipe section.

36. A method, as claimed in claim 33, wherein:

said product storage device comprises a wafer cassette and said plurality of product comprises a plurality of wafers, wherein said running step for each said wafer in said cassette is intended to be limited to said first plasma recipe, and wherein each of said identifying steps provides verification that this is the case.