Negative photoresist for silicon KOH etch without silicon nitride

• US 7,695,890 B2
• Filed: 09/06/2006
• Issued: 04/13/2010
• Est. Priority Date: 09/09/2005
• Status: Active Grant

• Current Assignee: Brewer Science Inc.
• Original Assignee: Brewer Science Inc.
• Inventors: Li, Chenghong, Malhotra, Jyoti K., Zhong, Xing-Fu
• Primary Examiner(s): Walke; Amanda C.
• Application Number:
  US11/470,520
• Publication Number:
  US 20070075309A1
• Time in Patent Office: 1,315 Days
• Field of Search: 430/270.1, 430/907, 430/914
• US Class Current: 430/270.1
• CPC Class Codes: G03F 7/0382 the macromolecular compound being present in a chemically amplified negative photoresist composition
• CPC Class Codes: G03F 7/0752 in non photosensitive layers or as additives, e.g. for dry lithography
• CPC Class Codes: H01L 21/3081 characterised by their composition, e.g. multilayer masks, materials
• CPC Class Codes: Y10S 430/108 Polyolefin or halogen containing
• CPC Class Codes: Y10S 430/115 Cationic or anionic

Abstract

New photoresists for use during the production of semiconductor and MEMS devices are provided. The primer layer preferably comprises a silane dissolved or dispersed in a solvent system. The photoresist layer includes copolymers prepared from styrene, acrylonitrile, and epoxy-containing monomers. The photoresist layer comprises a photoacid generator, and is preferably negative-acting.

Claims

1. A photosensitive composition useful as a protective layer, said composition being alkaline-resistant and negative-acting and said composition comprising a polymer and a photoacid generator dissolved or dispersed in a solvent system, said polymer comprising:

2. The composition of claim 1, wherein said monomer (III) is selected from the group consisting of glycidyl methacrylate, glycidyl acrylate, and vinylbenzyl glycidyl ether monomers.

3. The composition of claim 1, wherein said monomer (III) has the formula

4. The composition of claim 1, wherein said photoacid generator is selected from the group consisting of triarylsulfonium hexafluoroantimonate, triarylsulfonium hexafluoro-phosphate, diaryliodonium hexafluoroantimonate, diaryliodonium hexafluorophosphate,

5. The composition of claim 1, wherein said polymer comprises from about 35% to about 75% by weight of (I), from about 20% to about 40% by weight of(II), and from about 5% to about 15% by weight of (III), based upon the total weight of the polymer taken as 100% by weight.

6. A method of forming a microelectronic structure, said method comprising:

providing a microelectronic substrate;

applying a primer layer to said substrate, said primer layer comprising a silane dispersed or dissolved in a solvent system;

applying a photosensitive layer to said primer layer, said photosensitive layer comprising a photoacid generator and a polymer dispersed or dissolved in a solvent system, said

polymer comprising;

7. The method of claim 6, wherein said monomer (III) is selected from the group consisting of glycidyl methacrylate, glycidyl acrylate, and vinylbenzyl glycidyl ether monomers.

8. The method of claim 6, wherein said monomer (III) has the formula

9. The method of claim 6, wherein said photoacid generator is selected from the group consisting of triarylsulfonium hexafluoroantimonate, triarylsulfonium hexafluorophosphate, diaryliodonium hexafluoroantimonate, diaryliodonium hexafluorophosphate,

10. The method of claim 6, wherein said polymer comprises from about 35% to about 75% by weight of (I), from about 20% to about 40% by weight of(II), and from about 5% to about 15% by weight of (III), based upon the total weight of the polymer taken as 100% by weight.

11. The method of claim 6, wherein said silane having a formula selected from the group consisting of

12. The method of claim 6, said silane being selected from the group consisting of aminoalkoxysilanes, phenylsilanes, and diphenylsilanes.

13. The method of claim 12, wherein said silane is selected from the group consisting of aminoalkylalkoxysilanes and phenylaminoalkylalkoxysilanes.

14. The method of claim 12, wherein said silane is selected from the group consisting of aminopropyltrimethoxysilane, aminopropyltriethoxysilane, N-phenylaminopropyltrimethoxysilane, N-phenylaminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-mercaptopropyl-trimethoxysilane, phenyltrimethoxysilane, phenyltrichiorosilane, phenyhriethoxysilane, phenyltriacetoxysilane, diphenyldimethoxysilane, diphenyldichiorosilane, diphenylsilanediol 2-phenylethyltrialkoxysilane, p/m-chlorophenyltrimethoxysilane, p/m-bromophenyltrimethoxysilane,(p/m-chloromethyl)phenyltrimethoxysilane, 2-(p/m-methoxy)phenylethyltrimethoxysilane, 2-(p/m-chloromethyl)phenylethyltrimethoxysilane, 3,4-dichiorophenyltrichiorosilane, 3-phenoxypropyltrichlorosilane, 3-(N-phenylamino)propyltrimethoxysilane, and 2-(diphenylphosphino)ethyltriethoxysilane.

15. The method of claim 6, further comprising baking said primer layer after said primer layer applying.

16. The method of claim 15, wherein said primer layer further comprises a catalyst, and said primer layer baking results in crosslinking of said silane.

17. The method of claim 6, further comprising baking said photosensitive layer after said photosensitive layer applying.

18. The method of claim 17, wherein said baking causes the polymer of said photosensitive layer to covalently bond with the silane of said primer layer.

19. The method of claim 6, further comprising exposing a first portion of said photosensitive layer to actinic radiation while a second portion of said photosensitive layer is not exposed to actinic radiation.

20. The method of claim 19, wherein said first portion of said photosensitive layer crosslinks during said exposing.

21. The method of claim 20, further comprising baking said photosensitive layer after said exposing to actinic radiation.

22. The method of claim 20, further comprising developing said photosensitive layer.

23. The method of claim 22, wherein said developing results in the second portion of said photosensitive layer being substantially removed during said developing step so as to form a stack including a photosensitive layer having a pattern formed therein.

24. The method of claim 23, further comprising baking said photosensitive layer after said developing.

25. The method of claim 6, wherein said photosensitive layer exhibits less than about 100 μ

m of undercutting during etching.

26. The method of claim 6, wherein said substrate is selected from the group consisting of Si substrates, SiO₂ substrates, Si₃N₄ substrates, SiO₂ on silicon substrates, Si₃N₄ on silicon substrates, glass substrates, quartz substrates, ceramic substrates, semi conductor substrates, and metal substrates.

27. A microelectronic structure comprising:

a microelectronic substrate;

a primer layer adjacent said substrate, said primer layer comprising a crosslinked silane;

a photosensitive layer adjacent said primer layer, said photosensitive layer being alkaline-resistant and comprising a polymer comprising;

28. The microelectronic structure of claim 27, wherein said crosslinked epoxy group comprises

29. The microelectronic structure of claim 27, wherein said silane comprises an amine, and the polymer of said photosensitive layer comprises an epoxy group covalently bonded with said amine.

30. The microelectronic structure of claim 27, wherein said polymer comprises from about 35% to about 75% by weight of (I), from about 20% to about 40% by weight of (II), and from about 5% to about 15% by weight of (III), based upon the total weight of the polymer taken as 100% by weight.

31. The microelectronic structure of claim 27, said silane having a formula selected from the group consisting of

32. The microelectronic structure of claim 27, said silane being selected from the group consisting of aminoalkoxysilanes, phenylsilanes, and diphenylsilanes.

33. The microelectronic structure of claim 32, wherein said silane is selected from the group consisting of aminoalkylalkoxysilane and phenylaminoalkylalkoxysilanes.

34. The microelectronic structure of claim 32, wherein said silane is selected from the group consisting of aminopropyltrimethoxysilane, aminopropyltriethoxysilane, N-phenylaminopropyltrimethoxysilane, N-phenylaminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-mercaptopropyl-trimethoxysilane, phenyltrimethoxysilane, phenyltrichiorosilane, phenyltriethoxysilane, phenyltriacetoxysilane, diphenyldimethoxysilane, diphenyldichiorosilane, diphenylsilanediol 2-phenylethyltrialkoxysilane, p/m-chlorophenyltrimethoxysilane, p/m-bromophenyltrimethoxysilane,(p/m-chloromethyl)phenyltrimethoxysilane, 2-(p/m-methoxy)phenyl ethyltrimethoxysilane, 2-(p/m-chloromethyl)phenylethyltrimethoxysilane, 3,4-dichlorophenyltrichlorosilane, 3-phenoxypropyltrichiorosilane, 3-(N-phenylamino)propyltrimethoxysilane, and 2-(diphenylphosphino)ethyltriethoxysilane.

35. The microelectronic structure of claim 27, wherein said substrate is selected from the group consisting of Si substrates, SiO₂ substrates, Si₃N₄ substrates, SiO₂ on silicon substrates, Si₃N₄ on silicon substrates, glass substrates, quartz substrates, ceramic substrates, semiconductor substrates, and metal substrates.

36. A method of forming a microelectronic structure, said method comprising:

providing a microelectronic substrate selected from the group consisting of Si substrates, SiO₂ substrates, Si₃N₄ substrates, SiO₂ on silicon substrates, Si₃N₄ on silicon substrates, glass substrates, quartz substrates, ceramic substrates, semiconductor substrates, and metal substrates;

applying a primer layer to said substrate, said primer layer comprising a silane dispersed or dissolved in a solvent system;

applying a photosensitive layer to said primer layer, said photosensitive layer comprising a photoacid generator and a polymer dispersed or dissolved in a solvent system, said polymer comprising;