Fast photoresist model

• US 20120079436A1
• Filed: 09/28/2011
• Published: 03/29/2012
• Est. Priority Date: 09/29/2010
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Flagello, Donis G.
• Granted Patent: US 8,910,093 B2
• Time in Patent Office: Days
• US Class Current: 716/55
• CPC Class Codes: G03F 7/705 Modelling or simulating from physical phenomena up to complete wafer processes or whole workflow in wafer productions
• CPC Class Codes: G03F 7/70625 Dimensions, e.g. line width, critical dimension [CD], profile, sidewall angle or edge roughness

Abstract

A method of modeling an image intended to reside in a photoresist film on a substrate is provided. A simulated latent acid image of the image is produced, the simulated latent acid image is compressed in a predetermined direction, and developed to a pattern that enables (a) transfer of the pattern to the substrate or (b) further modeling of the pattern for transfer to the substrate.

Claims

1. A method of modeling an image intended to reside in a photoresist film on a substrate, comprising electronically producing a simulated latent acid image of the image, compressing the simulated latent acid image in a predetermined direction, and developing the simulated latent acid image to a pattern that enables transfer of the pattern to the substrate.

2. The method of claim 1, wherein compressing the simulated latent image comprises electronically averaging the simulated latent acid image in the predetermined direction.

3. The method of claim 1, wherein the simulated latent acid image is electronically referenced to a set of x, y and z axes, or to an optical axis that is used in producing the image on the substrate, and the predetermined direction comprises the z direction or along the optical axis.

4. The method of claim 3, wherein compressing the simulated latent image comprises electronically providing a weighted average for the simulated latent acid image along the predetermined direction.

5. The method of claim 4, wherein the bottom of the simulated latent image is weighted higher than the top part (which is close to the surface of the substrate).

6. The method of claim 1, further including creating a development rate profile of the simulated latent acid image.

7. The method of claim 6, further including creating a final resist height for the simulated latent acid image.

8. The method of claim 7, further including determining a critical dimension from the final resist height, for the simulated latent acid image.

9. The method of claim 8, further including applying a metrology offset to the resist height, to complete development of the pattern.

10. The method of claim 1, further comprising reshaping the simulated latent acid image by modeling techniques comprising (i) quenching the simulated latent acid image, (ii) post exposure bake, (iii) post exposure acid-base reaction, (iv) creation of inhibitor concentration from the simulated latent acid image, and (v) combinations of the foregoing.

11. A method of modeling an image intended to reside in a photoresist film on a substrate, comprising electronically producing a simulated latent acid image of the image, compressing the simulated latent acid image in a predetermined direction, and developing the simulated latent acid image to a pattern that enables further modeling of the pattern for transfer to the substrate.

12. The method of claim 11, wherein compressing the simulated latent image comprises electronically averaging the simulated latent acid image in the predetermined direction.

13. The method of claim 11, wherein the simulated latent acid image is electronically referenced to a set of x, y and z axes, or to an optical axis that is used in producing the image on the substrate, and the predetermined direction comprises the z direction or along the optical axis.

14. The method of claim 13, wherein compressing the simulated latent image comprises electronically providing a weighted average for the simulated latent acid image along the predetermined direction.

15. The method of claim 14, wherein the bottom of the simulated latent image is weighted higher than the top part (which is close to the surface of the substrate).

16. The method of claim 11, further including creating a development rate profile of the simulated latent acid image.

17. The method of claim 16, further including creating a final resist height for the simulated latent acid image.

18. The method of claim 17, further including determining a critical dimension from the final resist height, for the simulated latent acid image.

19. The method of claim 18, further including applying a metrology offset to the resist height, to complete development of the pattern.

20. The method of claim 11, further comprising reshaping the simulated latent acid image by modeling techniques comprising (i) quenching the simulated latent acid image, (ii) post exposure bake, (iii) post exposure acid-base reaction, (iv) creation of inhibitor concentration from the simulated latent acid image, and (v) combinations of the foregoing.