Method for improving OPC modeling

• US 20040139420A1
• Filed: 01/13/2003
• Published: 07/15/2004
• Est. Priority Date: 01/13/2003
• Status: Active Grant

• Current Assignee: Bell Semiconductor, LLC (Hilco Inc. (d/b/a Hilco Global))
• Original Assignee: LSI Logic Corporation (Broadcom, Inc.)
• Inventors: Bailey, George, Brist, Travis
• Granted Patent: US 6,934,929 B2
• Time in Patent Office: Days
• US Class Current: 716/21
• CPC Class Codes: G03F 1/36 Masks having proximity correction features; Preparation thereof, e.g. optical proximity correction [OPC] design processes
• CPC Class Codes: G03F 1/68 Preparation processes not covered by groups G03F1/20 - G03F1/50
• CPC Class Codes: G03F 7/70441 Optical proximity correction [OPC]
• CPC Class Codes: G03F 7/70608 Monitoring the unpatterned workpiece, e.g. measuring thickness, reflectivity or effects of immersion liquid on resist
• CPC Class Codes: G03F 7/70625 Dimensions, e.g. line width, critical dimension [CD], profile, sidewall angle or edge roughness
• CPC Class Codes: G03F 7/70641 Focus

Abstract

The invention provides a method for OPC modeling. The procedure for tuning a model involves collecting cross-section images and critical dimension measurements through a matrix of focus and exposure settings. These images would then run through a pattern recognition system to capture top critical dimensions, bottom critical dimensions, resist loss, profile and the diffusion effects through focus and exposure.

Claims

1. A method of tuning a model comprising the steps of:

a) collecting cross-section images and critical dimension measurements;

b) running said cross-section images through a pattern recognition system; and

c) capturing resultant data.

2. A method as defined in claim 1, wherein said cross-section images and said critical dimension measurements are collected through a matrix of focus and exposure setting.

3. A method as defined in claim 2, wherein said matrix of focus comprises negative focuses.

4. A method as defined in claim 3, wherein said negative focuses include −

0.60 micrometers, −

0.45 micrometers, −

0.30 micrometers and −

0.15 micrometers.

5. A method as defined in claim 2, wherein said matrix of focus comprises positive focuses.

6. A method as defined in claim 5, wherein said positive focuses comprise 0.15 micrometers, 0.30 micrometers, 0.45 micrometers, and 0.60 micrometers.

7. A method as defined in claim 2, wherein said matrix of focus comprises a best focus.

8. A method as defined in claim 7, wherein said best focus is 0.00 micrometers.

9. A method as defined in claim 1, wherein said resultant data includes top critical dimensions.

10. A method as defined in claim 1, wherein said resultant data includes bottom critical dimensions.

11. A method as defined in claim 1, wherein said resultant data includes resist loss.

12. A method as defined in claim 1, wherein said resultant data includes profile.

13. A method as defined in claim 1, wherein said resultant data includes diffusion effects through focus.

14. A method as defined in claim 1, wherein said cross-section images are collected by cleaving a wafer.

15. A method as defined in claim 1, wherein said cross-section images are collected through the use of a focused ion beam.

16. A method of OPC modeling comprising the steps of:

a) tuning a model at optimal dose and through focus using cross-sectional scanning electron microscope images;

b) collecting top down scanning electron microscope data through a matrix of focus and exposure settings; and

c) correlating said model to said top down scanning electron microscope data collected through a matrix of focus and exposure settings.