Process control with control signal derived from metrology of a repetitive critical dimension feature of a test structure on the work piece

• US 6,368,879 B1
• Filed: 09/22/1999
• Issued: 04/09/2002
• Est. Priority Date: 09/22/1999
• Status: Expired due to Term

• Current Assignee: GlobalFoundries, Inc.
• Original Assignee: Advanced Micro Devices, Inc.
• Inventors: Toprac, Anthony J.
• Primary Examiner(s): Bowers, Charles
• Assistant Examiner(s): PERT, EVAN T
• Application Number:
  US09/401,090
• Time in Patent Office: 930 Days
• Field of Search: 438/14, 438/5, 438/7, 438/8, 438/9, 438/16
• US Class Current: 438/5
• CPC Class Codes: G03F 7/70625 Dimensions, e.g. line width, critical dimension [CD], profile, sidewall angle or edge roughness
• CPC Class Codes: G05B 19/41875 characterised by quality surveillance of production
• CPC Class Codes: G05B 2219/37525 Mean, average values, statistical derived values
• CPC Class Codes: G05B 2219/37576 Post-process, measure worpiece after machining, use results for new or same
• CPC Class Codes: G05B 2219/45026 Circuit board, pcb
• CPC Class Codes: H01L 22/20 Sequence of activities consisting of a plurality of measurements, corrections, marking or sorting steps
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

A method is provided for manufacturing, the method including processing a workpiece in a processing step, measuring a critical dimension of features formed on the workpiece using a test structure formed on the workpiece, the test structure including a plurality of the features, and forming an output signal corresponding to the critical dimension measurements. The method also includes feeding back a control signal based on the output signal to adjust the processing performed in the processing step if the output signal corresponding to the critical dimension measurements indicates a predetermined tolerance value has been exceeded.

Claims

1. A method of manufacturing, the method comprising:

processing a work piece in a processing step;

measuring dimensions of a repetitive critical dimension feature of a test structure formed on the work piece to form a set of critical dimension measurements;

forming an output signal corresponding to a statistical analysis of the set of critical dimension measurements; and

feeding back a control signal based on the output signal to adjust the processing performed in the processing step if the output signal corresponding to the set of critical dimension measurements indicates a predetermined tolerance value has been exceeded.

2. The method of claim 1, wherein the measuring to form a set of critical dimension measurements includes measuring line widths of lines, wherein each of the lines is formed to have a line width representative of a gate line of a transistor.

3. The method of claim 1, wherein the measuring to form a set of critical dimension measurements includes measuring pitches between lines, wherein each adjacent pair of the lines is formed to have a pitch representative of spacing between adjacent lines of a transistor array.

4. The method of claim 1, wherein the measuring to form a set of critical dimension measurements includes measuring line widths of lines and pitches between the lines, wherein each of the lines is formed to have a line width representative of a line width of a gate line of a transistor and each adjacent pair of the lines is formed to have a pitch representative of spacing between adjacent lines of a transistor array.

5. The method of claim 1, wherein the measuring to form a set of critical dimension measurements includes using a scanning electron microscope.

6. The method of claim 5, wherein the measuring to form a set of critical dimension measurements includes measuring a dimension of every one of a plurality of repetitive critical dimension features of the test structure on the work piece.

7. The method of claim 1, wherein the forming an output signal corresponding to a statistical analysis of the set of critical dimension measurements includes forming a median value of the set of critical dimension measurements.

8. The method of claim 7, wherein the forming an output signal corresponding to a statistical analysis of the set of critical dimension measurements includes forming first and third quartile values, and an interquartile range of the set of critical dimension measurements.

9. The method of claim 1, wherein the forming the output signal corresponding to a statistical analysis of the set of critical dimension measurements includes forming a mean value of the set of critical dimension measurements.

10. The method of claim 9, wherein the forming the output signal corresponding to a statistical analysis of the set of critical dimension measurements includes forming a standard deviation value of the critical dimension measurements.

11. A method of manufacturing, the method comprising:

processing a work piece in a processing step, the processing step including forming a test structure on the work piece, the test structure including a repetitive feature representative of a critical dimension;

measuring dimensions of the repetitive feature to form a set of critical dimension measurements;

forming an output signal corresponding to a statistical analysis of the set of critical dimension measurements;

feeding back a control signal based on the output signal to adjust the processing performed in the processing step if the output signal corresponding to the statistical analysis of the set of critical dimension measurements indicates a predetermined tolerance value has been exceeded.

12. The method of claim 11, wherein the measuring to form a set of critical dimension measurements includes measuring line widths of lines, wherein each of the lines is formed to have a line width representative of a gate line width of a transistor.

13. The method of claim 11, wherein the measuring to form a set of critical dimension measurements includes measuring pitches between lines, wherein each adjacent pair of the lines is formed to have a pitch representative of the spacing between adjacent lines of a transistor array.

14. The method of claim 11, wherein the forming the output signal corresponding to a statistical analysis of the set of critical dimension measurements includes forming a median value, first and third quartile values, and an interquartile range of the set of critical dimension measurements.

15. The method of claim 11, wherein the forming the output signal corresponding to a statistical analysis of the set of critical dimension measurements includes forming a mean value and a standard deviation value of the set of critical dimension measurements.

16. A method of manufacturing, the method comprising:

processing a workpiece in a processing step, the processing step including forming a test structure on the workpiece, the test structure including a plurality of lines, each of the lines formed to have a line width of a gate line of a transistor, and each of adjacent pairs of the lines formed to have a pitch between adjacent lines of a transistor array;

measuring line widths of at least two of the plurality of the lines of the test structure;

measuring pitches between at least two of the adjacent pairs of the lines of the test structure;

forming an output signal corresponding to a statistical analysis of the line widths and pitches measurements; and

feeding back a control signal based on the output signal to adjust the processing performed in the processing step if the output signal corresponding to the line widths and pitches measurements indicates a predetermined tolerance value has been exceeded.

17. The method of claim 16, wherein forming the output signal corresponding to a statistical analysis of the line widths and pitches measurements includes forming median values of the line widths and pitches measurements.

18. The method of claim 17, wherein forming the output signal corresponding to a statistical analysis of the line widths and pitches measurements includes forming first and third quartile values, and interquartile ranges of the line widths and pitches measurements.

19. The method of claim 16, wherein forming the output signal corresponding to a statistical analysis of the line widths and pitches measurements includes forming mean values of the line widths and pitches measurements.

20. The method of claim 19, wherein forming the output signal corresponding to a statistical analysis of the line widths and pitches measurements includes forming standard deviation values of the line widths and pitches measurements.