Photolithographic patterning of devices

• US 10,503,065 B2
• Filed: 07/31/2015
• Issued: 12/10/2019
• Est. Priority Date: 08/01/2014
• Status: Active Grant

• Current Assignee: Orthogonal, Inc.
• Original Assignee: Orthogonal, Inc.
• Inventors: O'Toole, Terrence Robert, DeFranco, John Andrew, Byrne, Frank Xavier
• Primary Examiner(s): Duda, Kathleen
• Application Number:
  US15/501,128
• Publication Number:
  US 20170219921A1
• Time in Patent Office: 1,593 Days
• CPC Class Codes: C11D 7/505 Mixtures of (hydro)fluorocarbons
• CPC Class Codes: G03F 7/0002 Lithographic processes using patterning methods other than those involving the exposure to radiation, e.g. by stamping
• CPC Class Codes: G03F 7/0035 Multiple processes, e.g. applying a further resist layer on an already in a previously step, processed pattern or textured surface
• CPC Class Codes: G03F 7/0046 with perfluoro compounds, e.g. for dry lithography G03F7/0048 takes precedence
• CPC Class Codes: G03F 7/038 Macromolecular compounds which are rendered insoluble or differentially wettable G03F7/075 takes precedence; macromolecular azides G03F7/012; macromolecular diazonium compounds G03F7/021
• CPC Class Codes: G03F 7/0392 the macromolecular compound being present in a chemically amplified positive photoresist composition
• CPC Class Codes: G03F 7/0397 the macromolecular compound having an alicyclic moiety in a side chain
• CPC Class Codes: G03F 7/325 Non-aqueous compositions
• CPC Class Codes: G03F 7/40 Treatment after imagewise removal, e.g. baking
• CPC Class Codes: H10K 71/00 Manufacture or treatment specially adapted for the organic devices covered by this subclass
• CPC Class Codes: H10K 71/221 by lift-off techniques
• CPC Class Codes: H10K 71/233 by photolithographic etching
• CPC Class Codes: H10K 71/40 Thermal treatment, e.g. annealing in the presence of a solvent vapour

Abstract

A method of patterning a device is disclosed using a resist precursor structure having at least two fluoropolymer layers. A first fluoropolymer layer includes a first fluoropolymer material having a fluorine content of at least 50% by weight and is substantially soluble in a first hydrofluoroether solvent or in a first perfluorinated solvent, but substantially less soluble in a second hydrofluoroether solvent relative to both the first hydrofluoroether and the first perfluorinated solvent. The second fluoropolymer layer includes a second fluoropolymer material having a fluorine content less than that of the first fluoropolymer material and is substantially soluble in the first or second hydrofluoroether solvents, but substantially less soluble in the first perfluorinated solvent relative to both the first and second hydrofluoroether solvents.

Claims

1. A method of patterning a device, comprising:

a) over a device substrate, forming a resist precursor structure including

i) a first fluoropolymer layer including a first fluoropolymer material having a fluorine content of at least 50% by weight and substantially soluble in a first hydrofluoroether solvent or in a first perfluorinated solvent, but substantially less soluble in a second hydrofluoroether solvent relative to both the first hydrofluoroether and the first perfluorinated solvent, and

ii) a second fluoropolymer layer including a second fluoropolymer material having a fluorine content less than that of the first fluoropolymer material and substantially soluble in the first or second hydrofluoroether solvents, but substantially less soluble in the first perfluorinated solvent relative to both the first and second hydrofluoroether solvents; and

b) photo-lithographically forming a patterned resist structure and a complementary pattern of uncovered substrate, wherein such forming includes contact of at least a portion of the second fluoropolymer layer with a first fluorinated developing agent comprising the first or second hydrofluoroether solvent.

2. The method of claim 1 further including treating the device substrate to form an intermediate patterned device structure, wherein the patterned resist structure acts as mask.

3. The method of claim 1 further including removing a top layer of the patterned resist structure by contact with a lift-off agent comprising a third hydrofluoroether solvent that is optionally the same as the first hydrofluoroether solvent or the second hydrofluoroether solvent, or a second perfluorinated solvent that is optionally the same as first perfluorinated solvent.

4. The method of claim 1 wherein the resist precursor structure further comprises a third photopolymer layer provided over the first and second fluoropolymer layers.

5. The method of claim 4 wherein the third photopolymer layer is provided from a photosensitive polymer material composition comprising at least 50% by weight of one or more non-fluorinated coating solvents.

6. The method of claim 5 wherein the photo-lithographically forming step includes exposing the third photopolymer layer to patterned radiation to form an exposed photopolymer layer and contacting the exposed photopolymer layer with an aqueous or non-fluorinated organic developing agent to form a first pattern of photopolymer and a complementary second pattern of uncovered fluoropolymer.

7. The method of claim 6 wherein the first fluorinated developing agent comprises the first hydrofluoroether thereby removing uncovered portions of the first and second fluoropolymer layers to form the patterned resist structure and the complementary pattern of uncovered substrate corresponding to the second pattern.

8. The method of claim 6 wherein the second fluoropolymer layer is provided over the first fluoropolymer layer, and wherein the first fluorinated developing agent comprises the second hydrofluoroether which removes uncovered portions of the second fluoropolymer layer to form a pattern of uncovered first fluoropolymer layer.

9. The method of claim 8 further comprising contacting the uncovered first fluoropolymer layer with a second fluorinated developing agent comprising the first perfluorinated solvent or the first hydrofluoroether solvent to form the patterned resist structure and the complementary pattern of uncovered substrate corresponding to the second pattern.

10. The method of claim 6 wherein the first fluoropolymer layer is provided over the second fluoropolymer layer, and prior to contacting with the first fluorinated developing agent, further comprising contacting at least a portion of the first fluoropolymer layer with a second fluorinated developing agent comprising the first perfluorinated solvent.

11. The method of claim 5 wherein the third photopolymer layer further comprises a fluorinated surfactant.

12. The method of claim 4 wherein the third photopolymer layer is a negative tone photoresist.

13. The method of claim 4 wherein the first fluoropolymer layer is provided over the second fluoropolymer layer, and the third photopolymer layer is a photosensitive fluoropolymer provided from a composition comprising a hydrofluoroether coating solvent.

14. The method of claim 13 wherein the photo-lithographically-forming step includes exposing the third photopolymer layer to patterned radiation to form an exposed photopolymer layer and contacting the exposed photopolymer layer with the first fluorinated developing agent to form a first pattern of photopolymer.

15. The method of claim 14 wherein the first fluorinated developing agent comprises the first hydrofluoroether that further removes uncovered portions of the first and second fluoropolymer layers to form the patterned resist structure and the complementary pattern of uncovered substrate corresponding to the second pattern.

16. The method of claim 1 wherein the second fluoropolymer layer is a fluorinated photopolymer layer provided over the first fluoropolymer layer from a composition comprising the second fluoropolymer material, which is a photosensitive fluoropolymer material, and a hydrofluoroether coating solvent.

17. The method of claim 16 wherein the photo-lithographically-forming step includes exposing the fluorinated photopolymer layer to patterned radiation to form an exposed photopolymer layer and contacting the exposed photopolymer layer with the first fluorinated developing agent to form a first pattern of photopolymer.

18. The method of claim 17 wherein the first fluorinated developing agent comprises the first hydrofluoroether that further removes uncovered portions of the first and fluoropolymer layer to form the patterned resist structure and the complementary pattern of uncovered substrate corresponding to the second pattern.

19. The method of claim 1 wherein the first hydrofluoroether solvent is saturated having at least four more perfluorinated carbon atoms than hydrogen-containing carbon atoms.

20. The method of claim 1 wherein the first hydrofluoroether solvent is a saturated segregated hydrofluoroether having at least five perfluorinated carbon atoms and less than three hydrogen-containing carbon atoms.

21. The method of claim 1 wherein the second hydrofluoroether solvent is saturated having fewer than four more perfluorinated carbon atoms than hydrogen-containing atoms and has a fluorine content of at least 60% by weight.

22. The method of claim 1 wherein the second hydrofluoroether solvent is a saturated segregated hydrofluoroether having less than five perfluorinated carbon atoms or is a non-segregated hydrofluoroalkylether.

23. The method of claim 1 wherein the first perfluorinated solvent is an unsaturated perfluorocarbon, perfluoroether or perfluoroalkyl amine.

24. The method of claim 1 wherein the first fluoropolymer material comprises a fluorinated cyclic structure.

25. The method of claim 1 wherein the first fluoropolymer material comprises a perfluorinated cyclic ether or dioxol.

26. The method of claim 1 wherein the second fluoropolymer material is not perfluorinated.

27. The method of claim 1 wherein the second fluoropolymer material includes a repeating unit having a fully or partially fluorinated alkyl or alkyl ether group.

28. The method of claim 1 wherein the second fluoropolymer material includes a copolymer comprising a first repeating unit having a fluorinated group and a second repeating unit having a non-fluorinated alkyl or alkyl ether group.

29. The method of claim 1 wherein the second fluoropolymer material is formed from one or more monomers comprising an acrylate or an acrylate derivative.

30. The method of claim 1 wherein the patterned resist structure has an undercut profile.