USRE38282EExpiredUtilityPatentIndex 73

Process for using bilayer photoresist

Assignee: IBMPriority: Mar 28, 1997Filed: Jun 28, 2001Granted: Oct 21, 2003

Est. expiryMar 28, 2017(expired)· nominal 20-yr term from priority

Inventors:ALLEN ROBERT DAVID HOFER DONALD CLIFFORD SOORIYAKUMARAN RATNAM WALLRAFF GREGORY MICHAEL

G03F 7/0758G03F 7/0045Y10S430/111

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Claims

Abstract

The invention relates to a process for forming bilayer resist images with a chemically-amplified, radiation-sensitive bilayer resist. The bilayer resist is disposed on a substrate and comprises (i) a top imaging layer comprising a radiation-sensitive acid generator and a vinyl polymer having an acid-cleavable silylethoxy group and (ii) an organic underlayer. The bilayer resist is used in the manufacture of integrated circuits.

Claims

exact text as granted — not AI-modified

What is claimed is:

1. A process for generating a bilayer resist image on a substrate, comprising the steps of:
(a) coating a substrate with an organic underlayer;
(b) coating the organic underlayer with a top layer comprising
(i) a radiation sensitive acid generator, and
(ii) a polymer formed by polymerizing a C 5-20 cyclic olefin monomer optionally in combination with one or more additional monomers selected from the group consisting of acrylate, methacrylate, hydroxystyrene optionally substituted with C 1-6 alkyl, and combinations thereof, the polymer having an acid-cleavable silylethoxy group attached thereto wherein the ethoxy portion of the silylethoxy group is optionally substituted with C 1-6 alkyl, phenyl, or benzyl;
(c) imagewise exposing the top layer to radiation;
(d) developing the image in the top layer; and
(e) transferring the image through the organic underlayer to the substrate.

2. The process of claim 1 wherein the polymer is a copolymer formed by polymerizing the C 5-20 cyclic olefin monomer with hydroxystyrene, acrylate, methacrylate, or a combination thereof.

3. The process of claim 2 , wherein the polymer is a copolymer formed by polymerizing the C 5-20 cyclic olefin monomer with acrylate or methacrylate.

4. The process of claim 3 wherein the silylethoxy group is bonded to the acrylate or methacrylate.

5. The process of claim 4 wherein the silylethoxy group is tris (C 1-6 alkyl silyl) silylethoxy.

6. The process of claim 5 wherein the organic underlayer is diazonaphthoquinone novolac.

7. The process of claim 6 wherein the acid generator is iodonium triflate.

8. The process of claim 7 wherein the top layer is imagewise exposed to radiation having a wavelength of 193 nm or 248 nm.

9. The process of claim 8 wherein the top layer is imagewise exposed to radiation having a wavelength of 193 nm.

10. The process of claim 8 wherein the top layer is imagewise exposed to radiation having a wavelength of 248 nm.

11. The process of claim 2 , wherein the polymer is a homopolymer formed by polymerizing the C 5-20 cyclic olefin monomer in the absence of additional monomers.

12. A process of generating a bilayer resist image on a substrate comprising the steps of:
(a) coating a substrate with an organic underlayer;
(b) coating the organic underlayer with a top layer comprising
(i) a radiation-sensitive acid generator,
(ii) a polymer formed by polymerizing a C 5-20 cyclic olefin monomer optionally in combination with one or more additional monomers selected from the group consisting of acrylate, methacrylate, hydroxystyrene optionally substituted with C 1-6 alkyl, and combinations thereof, and
(iii) a compound having an acid-cleavable silylethoxy group;
(c) imagewise exposing the top layer to radiation;
(d) developing the image in the top layer; and
(c) transferring the image through the organic underlayer to the substrate.

13. The process of claim 12 wherein the compound of (b)(iii) is an androstane substituted with an acid-cleavable silylethoxy substituent.

14. The process of claim 13 wherein the ethoxy portion of the silylethoxy group is optionally substituted with C 1-6 alkyl, phenyl, or benzyl.

15. The process of claim 14 wherein the silylethoxy group is tris (C 1-6 alkyl silyl) silylethoxy.

16. The process of claim 12 , wherein the polymer is a copolymer formed by polymerizing the C 5-20 cyclic olefin monomer with acrylate or methacrylate.

17. The process of claim 12 , wherein the polymer is a homopolymer formed by polymerizing the C 5-20 cyclic olefin monomer in the absence of additional monomers.

18. The process of claim 12 , wherein the top layer is imagewise exposed to radiation having a wavelength of 193 nm or 248 nm.

19. The process of claim 18 wherein the top layer is imagewise exposed to radiation having a wavelength of 193 nm.

20. The process of claim 18 wherein the top layer is imagewise exposed to radiation having a wavelength of 248 nm.

21. A process for generating a bilayer resist image on a substrate, comprising the steps of:
(a) coating a substrate with an organic underlayer;
(b) coating the organic underlayer with a top layer comprising
(i) a radiation sensitive acid generator, and
(ii) a polymer formed by polymerizing one or more monomers selected from the group consisting of acrylate, methacrylate, hydroxystyrene optionally substituted with C 1-6 alkyl, C 5-20 cyclic olefin monomers, and combinations thereof, the polymer having acid-cleavable moieties bound thereto, wherein all such moieties are silylethoxy groups optionally substituted on the ethoxy portion thereof with C 1-6 alkyl, phenyl, or benzyl;
(c) imagewise exposing the top layer to radiation;
(d) developing the image in the top layer; and
(e) transferring the image through the organic underlayer to the substrate.

22. The process of claim 21 wherein the polymer is a copolymer formed by polymerizing the C 5-20 cyclic olefin monomer with hydroxystyrene, acrylate, methacrylate, or a combination thereof.

23. The process of claim 22 , wherein the polymer is a copolymer formed by polymerizing the C 5-20 cyclic olefin monomer with acrylate or methacrylate.

24. The process of claim 23 , wherein the silylethoxy group is bonded to the acrylate or methacrylate.

25. The process of claim 21 , wherein the polymer is a homopolymer formed by polymerizing the C 5-20 cyclic olefin monomer in the absence of additional monomers.

26. The process of claim 21 , wherein the top layer is imagewise exposed to radiation having a wavelength of 193 nm or 248 nm.

27. The process of claim 26 wherein the top layer is imagewise exposed to radiation having a wavelength of 193 nm.

28. The process of claim 26 wherein the top layer is imagewise exposed to radiation having a wavelength of 248 nm.

29. A process for generating a bilayer resist image on a substrate, comprising the steps of:
(a) coating a substrate with an organic underlayer, ;
(b) coating the organic underlayer with a top layer comprising a radiation-sensitive acid generator and a polymer formed by copolymerizing (i) hydroxystyrene optionally substituted with C 1-6 alkyl with (ii) a second monomer selected from the group consisting of acrylic acid and methacrylic acid substituted with an acid-cleavable silylethoxy group, wherein the ethoxy portion of the silylethoxy group is substituted with 0 to 4 C 1-6 alkyl, phenyl, or benzyl groups, and, optionally, with (iii) a third monomer optionally substituted with an acid-cleavable group;
(c) imagewise exposing the top layer to radiation;
(d) developing the image in the top layer; and
(e) transferring the image through the organic underlayer to the substrate.

30. The process of claim 29 , wherein the second monomer has the structure
wherein R is hydrido or methyl, the R′ are independently hydrido, C 1-6 alkyl, phenyl, or benzyl, and R 1 , R 2 and R 3 are independently selected from the group consisting of hydrido, C 1-6 alkyl and Si(R 4 ) 3 wherein R 4 is independently hydrido or lower alkyl.

31. The process of claim 30 , wherein R is methyl.

32. The process of claim 30 , wherein the polymer is formed by copolymerization of the first, second and third monomers.

33. The process of claim 32 , wherein the third monomer is substituted with an acid-cleavable group.

34. The process of claim 33 29 , wherein the third monomer is acrylic acid or methacrylic acid substituted with an acid-labile ester group.

35. The process of claim 34 , wherein the acid-labile ester group is t-butyl ester.

36. The process of claim 35 , wherein the R′ are independently hydrido or C 1-6 alkyl.

37. The process of claim 36 , wherein all R′ are hydrido.

38. A process for preparing a composition useful as an upper layer in a bilayer resist, comprising:
admixing ( a ) a radiation sensitive acid generator and ( b ) a polymer comprising C 5-20 cyclic olefin monomer and optionally one or more additional monomers selected from the group consisting of acrylate, methacrylate, hydroxystyrene optionally substituted with C 1-6 alkyl, and combinations thereof, said polymer having an acid - cleavable silylethoxy group attached thereto wherein the ethoxy portion of the silylethoxy group is optionally substituted with C 1-6 alkyl, phenyl, or benzyl.

39. The process of claim 38 , wherein the polymer is a copolymer comprising ( i ) C 5-20 cyclic olefin monomer and ( ii ) a monomer selected from the group consisting of hydroxystyrene, acrylate, methacrylate, and combinations thereof.

40. The process of claim 39 , wherein the polymer is a copolymer comprising ( i ) C 5-20 cyclic olefin monomer and ( ii ) a monomer selected from the group consisting of acrylate and methacrylate.

41. The process of claim 40 wherein the silylethoxy group is bonded to the acrylate or methacrylate.

42. The process of claim 41 wherein the silylethoxy group is tris ( C 1-6 alkyl silyl ) silylethoxy.

43. The process of claim 39 , wherein the polymer is a homopolymer formed by polymerizing the C 5-20 cyclic olefin monomer in the absence of additional monomers.

44. The process of claim 38 wherein the acid generator is iodonium triflate.

45. The process of claim 38 , wherein said admixing is carried out in a solvent for the acid generator and polymer.

46. A process for preparing a composition useful as an upper layer in a bilayer resist, said process comprising:
admixing ( a ) a radiation sensitive acid generator, ( b ) a polymer comprising C 5-20 cyclic olefin monomer and optionally one or more additional monomers selected from the group consisting of acrylate, methacrylate, hydroxystyrene optionally substituted with C 1-6 alkyl, and combinations thereof, and ( c ) a compound having an acid - cleavable silylethoxy group.

47. The process of claim 46 wherein the compound of ( c ) is an androstane substituted with an acid - cleavable silylethoxy substituent.

48. The process of claim 47 wherein the ethoxy portion of the silylethoxy group is optionally substituted with C 1-6 alkyl, phenyl, or benzyl.

49. The process of claim 48 wherein the silylethoxy group is tris ( C 1-6 alkyl silyl ) silylethoxy.

50. The process of claim 46 , wherein the polymer is a copolymer comprising ( i ) C 5-20 cyclic olefin monomer and ( ii ) a monomer selected from the group consisting acrylate and methacrylate.

51. The process of claim 46 , wherein the polymer is a homopolymer formed by polymerizing the C 5-20 cyclic olefin monomer in the absence of additional monomers.

52. The process of claim 46 , wherein said admixing is carried out in a solvent for the acid generator and polymer.

53. A process for preparing a composition useful as an upper layer in a bilayer resist, comprising the steps of:
admixing ( a ) a radiation sensitive acid generator and ( b ) a polymer comprising ( i ) hydroxystyrene optionally substituted with C 1-6 alkyl, ( ii ) a second monomer selected from the group consisting of acrylic acid and methacrylic acid substituted with an acid - cleavable silylethoxy group, wherein the ethoxy portion of the silylethoxy group is substituted with 0 to 4 C 1-6 alkyl, phenyl, or benzyl groups, and ( iii ) a third monomer substituted with an acid - cleavable group.

54. The process of claim 53 , wherein the second monomer has the structure
wherein R is hydrido or methyl, the R′ are independently hydrido, C 1-6 alkyl, phenyl, or benzyl, and R 1 , R 2 and R 3 are independently selected from the group consisting of hydrido, C 1-6 alkyl and Si ( R 4 ) 3 wherein R 4 is independently hydrido or lower alkyl.

55. The process of claim 54 , wherein R is methyl.

56. The process of claim 53 , wherein the third monomer is acrylic acid or methacrylic acid substituted with an acid- labile ester group.

57. The process of claim 56 , wherein the acid- labile ester group is t - butyl ester.

58. The process of claim 57 , wherein the R′ are independently hydrido or C 1-6 alkyl.

59. The process of claim 58 , wherein all R′ are hydrido.

60. The process of claim 53 , wherein the admixing is carried out in a solvent for the acid generator and polymer.

61. A composition useful as an upper layer in a bilayer resist, comprising:
( a ) a radiation sensitive acid generator, and
( b ) a polymer comprising a C 5-20 cyclic olefin monomer and optionally one or more additional monomers selected from the group consisting of acrylate, methacrylate, hydroxystyrene optionally substituted with C 1-6 alkyl, and combinations thereof, said polymer having an acid - cleavable silylethoxy group attached thereto wherein the ethoxy portion of the silylethoxy group is optionally substituted with C 1-6 alkyl, phenyl, or benzyl.

62. The composition of claim 61 , wherein the polymer is a copolymer comprising ( i ) C 5-20 cyclic olefin monomer and ( ii ) monomer selected from the group consisting of hydroxystyrene, acrylate, methacrylate, and combinations thereof.

63. The composition of claim 62 , wherein the polymer is a copolymer comprising ( i ) C 5-20 cyclic olefin monomer and ( ii ) a monomer selected from the group consisting of acrylate and methacrylate.

64. The composition of claim 63 , wherein the silylethoxy group is bonded to the acrylate or methacrylate.

65. The composition of claim 64 , wherein the silylethoxy group is tris ( C 1-6 alkyl silyl ) silylethoxy.

66. The composition of claim 61 , wherein the acid generator is iodonium triflate.

67. The composition of claim 61 , wherein the polymer is a homopolymer of C 5-20 cyclic olefin monomer.

68. A composition useful as an upper layer in a bilayer resist, comprising:
( a ) a radiation sensitive acid generator, and
( b ) a polymer comprising a C 5-20 cyclic olefin monomer and optionally one or more monomers selected from the group consisting of acrylate, methacrylate, hydroxystyrene optionally substituted with C 1-6 alkyl, and combinations thereof, and
( c ) a compound having an acid - cleavable silylethoxy group.

69. The composition of claim 68 , wherein the compound of ( c ) is an androstane substituted with an acid - cleavable silylethoxy substituent.

70. A process of claim 69 , wherein the ethoxy portion of the silylethoxy group is optionally substituted with C 1-6 alkyl, phenyl, or benzyl.

71. A composition of claim 70 , wherein the silylethoxy group is tris ( C 1-6 alkyl silyl ) silylethoxy.

72. The composition of claim 68 , wherein the polymer is a copolymer comprising ( i ) C 5-20 cyclic olefin monomer and ( ii ) a monomer selected from the group consisting of acrylate and methacrylate.

73. The composition of claim 68 , wherein the polymer is a homopolymer formed by polymerizing the C 5-20 cyclic olefin monomer in the absence of additional monomers.

74. The composition of claim 68 being useful for imagewise exposure to radiation having a wavelength of 193 nm or 248 nm.

75. A composition useful as an upper layer in a bilayer resist, said composition comprising:
( a ) a radiation sensitive acid generator; and
( b ) a polymer comprising
( i ) hydroxystyrene optionally substituted with C 1-6 alkyl,
( ii ) a second monomer selected from the group consisting of acrylic acid and methacrylic acid substituted with an acid - cleavable silylethoxy group, wherein the ethoxy portion of the silylethoxy group is substituted with 0 to 4 C 1-6 alkyl, phenyl, or benzyl groups, and
( iii ) a third monomer substituted with an acid - cleavable group.

76. The composition of claim 75 , wherein the second monomer has the structure
wherein R is hydrido or methyl, the R′ are independently hydrido, C 1-6 alkyl, phenyl, or benzyl, and R 1 , R 2 and R 3 are independently selected from the group consisting of hydrido, C 1-6 alkyl and Si ( R 4 ) 3 wherein R 4 is independently hydrido or lower alkyl.

77. The composition of claim 75 , wherein R is methyl.

78. The composition of claim 75 , wherein the third monomer is acrylic acid or methacrylic acid substituted with an acid- labile ester group.

79. The composition of claim 78 , wherein the acid- labile ester group is t - butyl ester.

80. The composition of claim 79 , wherein the R′ are independently hydrido or C 1-6 alkyl.

81. The composition of claim 80 , wherein all R′ are hydrido.

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