Method and system of dynamic learning through a regression-based library generation process

• US 6,961,679 B2
• Filed: 05/27/2004
• Issued: 11/01/2005
• Est. Priority Date: 08/06/2001
• Status: Expired due to Term

• Current Assignee: Tokyo Electron America Incorporated (Tokyo Electron Limited)
• Original Assignee: Timbre Technologies Incorporated (Tokyo Electron Limited)
• Inventors: Jakatdar, Nickhil, Niu, Xinhui
• Primary Examiner(s): Tsai, Carol S. W.
• Application Number:
  US10/857,002
• Publication Number:
  US 20040220760A1
• Time in Patent Office: 523 Days
• Field of Search: 702/66, 702/67, 702/69, 702/70, 702/72, 702 74- 76, 702/81, 702 84- 86, 702117-120, 702/123, 702/151, 702/159, 702/189, 702/193, 702/FOR.104, 702/FOR.117, 702/FOR.114, 702/FOR.108, 702/FOR.110, 702FOR 135-137, 702/FOR.148, 702FOR 155-157, 702FOR 159-160, 702/FOR.165, 702FOR 170-171, 438 5-131, 438/800, 118/663, 118/675, 118/679, 716/4, 356/629, 356/634, 356/635, 356/636, 356/638, 356/639, 356/902, 706/12, 706/20, 706/46, 706/934
• US Class Current: 702/189
• CPC Class Codes: G01B 11/24 for measuring contours or curvatures
• CPC Class Codes: G01N 21/211 Ellipsometry optical thickness measurement G01B11/06

Abstract

The present invention relates to a method and system for efficiently determining grating profiles using dynamic learning in a library generation process. The present invention also relates to a method and system for searching and matching trial grating profiles to determine shape, profile, and spectrum data information associated with an actual grating profile.

Claims

1. A method of determining a profile, comprising:

receiving a set of measurements associated with an actual signal;

searching a profile library for a closest matching set of trial parameter values, wherein the set of trial parameter values is associated with a trial signal;

determining whether the trial signal satisfies a goodness of fit threshold;

if the trial signal satisfies the threshold, displaying the closest matching set of trial parameter values; and

if the trial signal does not satisfy the threshold, generating a new trial signal using the set of trial parameter values and storing the new trial signal in the profile library.

2. The method of claim 1, wherein if the trial signal does not satisfy the threshold, communicating an error message.

3. The method of claim 1, wherein if the trial signal does not satisfy the threshold, changing at least one parameter range associated with at least one of the trial parameter values.

4. The method of claim 1, wherein if the trial signal does not satisfy the threshold, increasing at least one parameter range associated with at least one of the trial parameter values.

5. A computer program product for use in determining a profile, said computer program product comprising:

a computer usable medium including computer readable program code embodied in said medium for causing determining the profile;

computer readable program code for causing a computer to effect receiving a set of measurements associated with an actual signal;

computer readable program code for causing said computer to effect searching a profile library for a closest matching set of trial parameter values, wherein the set of trial parameter values is associated with a trial signal;

computer readable program code for causing said computer to effect determining whether the trial signal satisfies a goodness of fit threshold;

if the trial signal satisfies the threshold, computer readable program code for causing said computer to effect displaying the closest matching set of trial parameter values; and

if the trial signal does not satisfy the threshold, computer readable program code for causing said computer to effect generating a new trial signal using the set of trial parameter values and storing the new trial signal in the profile library.

7. The computer program product of claim 5, wherein if the trial signal does not satisfy the threshold,

computer readable program code for causing said computer to effect communicating an error message.

9. The computer program product of claim 5, wherein if the trial signal does not satisfy the threshold,

computer readable program code for causing said computer to effect changing at least one parameter range associated with at least one of the trial parameter values.

11. The computer program product of claim 5, wherein if the trial signal does not satisfy the threshold,

computer readable program code for causing said computer to effect increasing at least one parameter range associated with at least one of the trial parameter values.

6. An article of manufacture comprising:

a computer usable medium including computer readable program code embodied therein for causing determining a profile, the computer readable program code in said article of manufacture comprising;

computer readable program code for causing a computer to effect receiving a set of measurements associated with an actual signal;

computer readable program code for causing said computer to effect searching a profile library for a closest matching set of trial parameter values, wherein the set of trial parameter values is associated with a trial signal;

computer readable program code for causing said computer to effect determining whether the trial signal satisfies a goodness of fit threshold;

if the trial signal satisfies the threshold, computer readable program code for causing said computer to effect displaying the closest matching set of trial parameter values; and

if the trial signal does not satisfy the threshold, computer readable program code for causing said computer to effect generating a new trial signal using the set of trial parameter values and storing the new trial signal in the profile library.

8. The article of manufacture of claim 6, wherein if the trial signal does not satisfy the threshold,

computer readable program code for causing said computer to effect communicating an error message.

10. The article of manufacture of claim 6, wherein if the trial signal does not satisfy the threshold,

computer readable program code for causing said computer to effect changing at least one parameter range associated with at least one of the trial parameter values.

12. The article of manufacture of claim 6, wherein if the trial signal does not satisfy the threshold,

computer readable program code for causing said computer to effect increasing at least one parameter range associated with at least one of the trial parameter values.