Methods for monitoring photoresists

• US 20030036006A1
• Filed: 03/26/2002
• Published: 02/20/2003
• Est. Priority Date: 03/26/2001
• Status: Active Grant

• Current Assignee: Shipley Company, LLC (Dow, Inc.), Yale University
• Original Assignee: Shipley Company, LLC (Dow, Inc.)
• Inventors: Feke, Gilbert D., Cameron, James F., Pohlers, Gerhard, Grober, Robert D.
• Granted Patent: US 6,770,407 B2
• Time in Patent Office: Days
• US Class Current: 430/30
• CPC Class Codes: G03F 7/105 having substances, e.g. indicators, for forming visible images
• CPC Class Codes: G03F 7/38 Treatment before imagewise removal, e.g. prebaking G03F7/265 takes precedence
• CPC Class Codes: G03F 7/70675 Latent image, i.e. measuring the image of the exposed resist prior to development

Abstract

Methods of the invention include fluorescence microscopy inspection of an imaged resist layer prior to any type of development processing. Preferred resists for use in the methods of the invention contain a component that facilitates monitoring of a resist coating layer, particularly a component that can function as a proton acceptor and have a change in fluorescence upon exposure to radiation reemployed to pattern an image in the resist coating layer.

Claims

1. A method for monitoring a photoresist relief image comprising:

exposing a photoresist coating layer to patterned activating radiation to form a latent relief image; and

analyzing the latent image prior to post-exposure thermal treatment or development of the resist coating layer.

2. The method of claim 1 wherein the latent image is analyzed by spectroscopy or microscopy.

3. The method of claim 1 or 2 wherein fluorescence of the latent image is analyzed.

4. The method of any one of claims 1 through 3 wherein the photoresist is a chemically amplified resist.

5. The method of any one of claims 1 through 4 wherein the photoresist is a positive-acting resist.

6. The method of any one of claims 1 through 4 wherein the photoresist is a negative-acting resist.

7. The method of any one of claims 1 through 6 wherein the focus of an apparatus employed to expose the photoresist is calibrated based on the analysis of the latent image.

8. The method of any one of claims 1 through 7 wherein the photoresist comprises a component that has a modulation in fluorescence in the presence of photoacid.

9. The method of any one of claims 1 through 8 wherein the photoresist comprises a component, separate from a photoacid generator compound, that is responsive to photoacid used to form a relief image in the photoresist layer.

10. The method of any one of claims 8 or 9 wherein the photoresist comprises a component that can accept a proton.

11. The method of claim 10 wherein the component is an aromatic compound.

12. The method of any one of claims 1 through 11 wherein the photoresist coating layer is thermally treated and developed to provide a relief image after analyzing the latent image.

13. A method for adjusting a photoresist exposure apparatus, comprising:

exposing a photoresist coating layer to patterned activating radiation to form a latent relief image;

analyzing the latent image prior to post-exposure thermal treatment or development of the resist coating layer; and

adjusting the photoresist exposure apparatus.

14. The method of claim 13 wherein the exposure apparatus is adjusted based on analysis of the latent image.

15. The method of claim 13 or 14 wherein the focus of the exposure apparatus is calibrated based on the analysis of the latent image.

16. The method of any one of claims 13 through 15 wherein the latent image is analyzed by spectroscopy or microscopy.

17. The method of any one of claims 13 through 16 wherein fluorescence of the latent image is analyzed.

18. , The method of any one of claims 13 through 17 wherein the photoresist is a chemically amplified resist.

19. The method of any one of claims 13 through 18 wherein the photoresist is a positive-acting resist.

20. The method of any one of claims 13 through 18 wherein the photoresist is a negative-acting resist.

21. The method of any one of claims 13 through 20 wherein the photoresist comprises a component that that has a modulation in fluorescence in the presence of photoacid.

22. The method of any one of claims 13 through 21 wherein the photoresist comprises a component, separate from a photoacid generator compound, that is responsive to photoacid used to form a relief image expose the photoresist layer.

23. The method of any one of claims 21 or 22 wherein the photoresist comprises a component that can accept a proton.

24. The method of any one of claims 21 through 23 wherein the component is an aromatic compound.

25. The method of any one of claims 13 through 24 wherein the photoresist coating layer is thermally treated and developed to provide a relief image after analyzing the latent image.

26. A system for visualizing a latent image patterned into a photoresist composition, comprising:

a coating layer of a photoresist composition on a substrate, the photoresist composition comprising a fluorescent dye compound;

a photoresist exposure tool; and

a tool to detect fluorescence of the photoresist composition after exposure of the coating layer to patterned activating radiation.

27. The system of claim 26 wherein the photoresist composition comprises a phenolic resin and the exposure tool provides radiation having a wavelength of about 248 nm.

28. The system of claim 26 wherein the photoresist composition comprises a resin that is substantially free of aromatic groups and the exposure tool provides radiation having a wavelength of less than 200 nm.

29. The system of claim 28 wherein the exposure tool provides radiation having a wavelength of about 193 nm.