Method and apparatus for monitoring plasma processing operations

• US 20030136663A1
• Filed: 06/06/2002
• Published: 07/24/2003
• Est. Priority Date: 04/23/1998
• Status: Abandoned Application

• Current Assignee: Sandia Corporation (Martin Marietta Corporation)
• Original Assignee: Sandia Corporation (Martin Marietta Corporation)
• Inventors: Denise Ward, Pamela Peardon, Stevenson, Joel O?apos;Don, Smith, Michael Lane Jr.
• Application Number:
  US10/163,624
• Publication Number:
  US 20030136663A1
• Time in Patent Office: Days
• US Class Current: 204/192.13
• 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. 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. 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 plasma monitoring system for a plasma process performed in a processing chamber, wherein said plasma process comprises a first plasma step, and wherein a first endpoint of said first plasma step is when a first predetermined result has been achieved, said system comprising:

a computer-readable storage medium comprising;

a first output associated with at least a portion of one of said first plasma steps, said first output being data representative of optical emissions from said processing chamber during execution of one of said first plasma steps within said processing chamber, wherein said optical emissions are within a first wavelength range extending from about 250 nanometers to about 1,000 nanometers and at least at every 1 nanometer within said first wavelength range;

means for identifying when said first endpoint has occurred for a current said first plasma step, wherein said means for identifying comprises a first technique comprising;

means for receiving data representative of optical emissions of said plasma in said processing chamber at least within said first wavelength range, at least a plurality of different constant during said current said first plasma step, and at least at every 1 nanometer within said first wavelength range;

means for comparing said optical emissions at each of said plurality of different times with said first output; and

means for determining when said optical emissions from at least one of said plurality of different times is within a predetermined amount of said first output at which time said first endpoint for said current said first plasma step is deemed to have been reached.

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

said plasma process is selected from the group consisting of a plasma recipe which is run on at least one product in said processing chamber, a plasma cleaning operation, a plasma conditioning operation, and a qualification wafer operation.

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

said means for determining step comprises means for obtaining a differential between optical emissions at each of said plurality of times and said first output, and wherein said predetermined amount is when said differential is free from any substantial peaks.

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

said optical emissions at each of said plurality of different times has an associated pattern and said first output has a first output pattern, wherein said means for comparing comprises means for comparing said pattern of said optical emissions at each of said plurality of different times with said first output pattern, and wherein said predetermined amount of said means for determining defines when said pattern of said optical emissions from at least one of said plurality of different times is at least substantially a match with said first output pattern.

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

said first output comprises said optical emissions from an earlier of said plurality of different times from said current said first plasma step.

6. A system, as claimed in claim 5, wherein:

said first output is said optical emissions from an immediately preceding time from said current said first plasma step.

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

said first output was obtained from an execution of said first plasma step previous to said current said first plasma step.

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

said means for identifying comprises a second technique which is different from said first technique, and wherein said first endpoint is identifiable by at least one of said first and second techniques.

9. A system, as claimed in claim 8, wherein:

said second technique is selected from the group consisting of means for determining when there is at least a first change in an impedance of said processing chamber and means for evaluating at least one individual wavelength of said plasma in said processing chamber at least a plurality of times during said current said first plasma step.

10. A system, as claimed in claim 8, wherein:

said second technique is selected from the group consisting of means for determining when there is at least a first change in an impedance of said processing chamber, means for evaluating at least one individual wavelength of said plasma in said processing chamber at least a plurality of times during said current said first plasma step in relation to a conformity with a predetermined function, and means for evaluating at least one individual wavelength of said plasma in said processing chamber at least a plurality of times during said current said first plasma step in relation to an output of at least one derivative of said predetermined function.

11. A system, as claimed in claim 1, wherein said computer-readable storage medium further comprises:

means for assessing a condition of said plasma during said current said first plasma step from data on said current said first plasma step provided to said means for receiving, wherein said condition is a cumulative result of all parameters having an effect on said plasma in said processing chamber.

12. A system, as claimed in claim 1, wherein said plasma process comprises a second plasma step which is different from said first plasma step, wherein a second endpoint of said second plasma step is when a second predetermined result of said second plasma step has been achieved, and wherein said computer-readable medium further comprises:

a second output associated with at least a portion of one of said second plasma steps, said second output being data representative of optical emissions from said processing chamber during execution of one of said second plasma steps within said processing chamber, wherein said optical emissions are at least within said first wavelength range and at least at every 1 nanometers within said first wavelength range;

means for identifying an occurrence of said second endpoint for a current said second plasma step.

13. A system for running a plasma process in a processing chamber, wherein said plasma process comprises a first plasma step, wherein a first endpoint of said first plasma step is when a first predetermined result of said first plasma step has been achieved, said system comprising:

a processing chamber;

a first gas inlet and a first gas outlet fluidly interconnected with said processing chamber;

a plasma generator in said plasma chamber, wherein said first plasma step may be run in said processing chamber after activation of said plasma generator; and

a computer-readable storage medium comprising;

a first output associated with at least a portion of one of said first plasma steps, said first output being data representative of optical emissions from said processing chamber during execution of one of said first plasma steps within said processing chamber, wherein said optical emissions are within a first wavelength range extending from about 250 nanometers to about 1,000 nanometers and at least at every 1 nanometer within said first wavelength range;

means for identifying when said first endpoint has occurred for a current said first plasma step, wherein said means for identifying comprises a first technique comprising;

means for receiving data representative of optical emissions of said plasma in said processing chamber at least within said first wavelength range, at least a plurality of different constant during said current said first plasma step and at least at every 1 nanometer within said first wavelength range;

means for comparing said optical emissions at each of said plurality of different times with said first output; and

means for determining when said optical emissions from at least one of said plurality of different times is within a predetermined amount of said first output at which time said first endpoint for said current said first plasma step is deemed to have been reached.