US4405707A
Expired / Lapsed
US
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Method of producing relief structures for integrated semiconductor circuits
Assignee: Siemens AG
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Filing: 1981-07-16
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Granted: 1983-09-20
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Expires: 2001-07-16
Abstract
Abstract Relief structures comprised of double lacquer layers on substrates already having relief structures for integrated semiconductor circuits are produced by applying a lower lacquer layer onto such substrate and which is composed of a material which does not cross-link or decompose due to radiation energy and which has only relatively slight sensitivity at the radiation energy dosage range utilized for structuring; applying an upper lacquer layer onto the lower lacquer layer and which upper layer is thinner relative to the thickness of the lower layer by a factor of at least 2 and is composed of a highly sensitive negative lacquer material; generating desired relief structures in the upper lacquer layer and removing those portions of the lower lacquer which are not covered by the upper negative lacquer layer.
Inventors
- 👤 Hartwig Bierhenke
- 👤 Siegfried Birkle
- 👤 Roland Rubner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:10
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/004; G03F7/09; G03F7/095; G03F7/094; H; H10; H10P; H10P14/00; H10P14/60; H10P14/68; H10P14/683
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
178 words
In a method for producing relief structures comprised of double lacquer layers on substrates which already contain relief structures for integrated semiconductor circuits wherein high-energy radiation, such as particulate or photon radiation, is utilized for structuring, the improvement comprising: applying said double lacquer layer to said substrate with a lower lacquer layer positioned directly on said substrate and an upper lacquer layer positioned on said lower lacquer layer; said lower lacquer layer being composed of a decomposable positive lacquer material which is only somewhat sensitive to particulate or photon radiation and having a sensitivity in the range of about 10 through 100 μm C/cm 2 ; said upper lacquer layer being thinner relative to the thickness of said lower lacquer layer by at least a factor of 2 and being comprised of a highly sensitive negative lacquer material having sensitive of less than about 5 μm C/cm 2 ; generating desired relief structures in said upper negative lacquer layer; and removing those portions of said lower lacquer layer which are not covered by said upper negative lacquer layer.
Claim 2
Dependent Claim
178 words
In a method for producing relief structures comprised of double lacquer layers on substrates which already contain relief structures for integrated semiconductor circuits wherein high-energy radiation, such as particulate or photon radiation, is utilized for structuring, the improvement comprising: applying said double lacquer layer to said substrate with a lower lacquer layer positioned directly on said substrate and an upper lacquer layer positioned on said lower lacquer layer; said lower lacquer layer being composed of a decomposable positive lacquer material which is only somewhat sensitive to particulate or photon radiation and having a sensitivity in the range of about 10 through 100 μm C/cm 2 ; said upper lacquer layer being thinner relative to the thickness of said lower lacquer layer by at least a factor of 2 and being comprised of a highly sensitive negative lacquer material having sensitive of less than about 5 μm C/cm 2 ; generating desired relief structures in said upper negative lacquer layer; and removing those portions of said lower lacquer layer which are not covered by said upper negative lacquer layer.
Claim 3
Dependent Claim
45 words
In a method as defined in claim 1 wherein said upper negative lacquer layer is applied at a layer thickness ranging from about 0.1 through 1.0 μm and said lower lacquer layer is applied in a layer thickness ranging from about 0.2 through 3.0 μm.
Claim 4
Dependent Claim
69 words
In a method as defined in claim 1 wherein generating desired relief structures in said upper negative lacquer layer includes applying a negative lacquer mask onto said upper negative lacquer layer prior to exposure to radiation; and removing those portions of said lower positive lacquer layer which are not covered by said mask are removed substantially simultaneously with development of the non-irradiated areas of said upper negative lacquer layer.
Claim 5
Dependent Claim
55 words
In a method as defined in claim 3 wherein said non-irradiated areas of said negative lacquer layer are removed by a developer selected from the group consisting of methyl ethyl ketone, methyl isobutyl ketone, a mixture of methyl ethyl ketone and ethanol or isopropanol and a mixture of methyl isobutyl ketone and ethanol or isopropanol.
Claim 6
Dependent Claim
68 words
In a method as defined in claim 1 wherein said lower lacquer layer is composed of material selected from the group consisting of polyphenyleneoxide; polyethersulfone; polycarbonate; polymethacrylimide; novolak/diazochinone mixtures; polyolefinsulfones; polystyrolsulfones; polyalkylmethacrylates; copolymers and methylmethacrylate with a material selected from the group consisting of α--Cl-- acrylates, α--CN-- acrylates and methacrylnitrile; copolymers of methacrylate with fluoridated ester compounds; polybenzylmethacrylate; polymethylisopropenyl ketones; polyisobutylenes and copolymers thereof; and α-cyano-ethylacrylate- α-amidoethylacrylate copolymers.
Claim 7
Dependent Claim
24 words
In a method as defined in claim 5 wherein said polyolefin sulfones are selected from the group consisting of polybutene-1-sulfone and cyclic polyolefin sulfone.
Claim 8
Dependent Claim
13 words
In a method as defined in claim 5 wherein said polyalkylmethacrylate is polymethylmethacrylate.
Claim 9
Dependent Claim
77 words
In a method as defined in claim 1 wherein said upper negative lacquer layer is composed of a material selected from the group consisting of glycidyl methacrylate; copolymers of glycidyl methacrylate (glycidyl acrylate) and a material selected from the group consisting of styrol, ethyl acrylate, epoxied butadiene, isoprene, polyacrylamide, polyvinylchloride, polysiloxane, a cyclic polyisoprene/diazide mixture (KTFR), polystyrol, polyvinylcarbazol, a halogenated polystyrol, polyvinylcarbazol, chlormethylated polystyrol, a cyclic polyisoprene/diazide mixture (KMER) methylmethacrylate-ethyl acrylate-glycidymethacrylate-terpolymer, partially esterified with 2-methacrylic acid (CER).
Claim 10
Dependent Claim
24 words
In a method as defined in claim 1 wherein said upper negative lacquer layer is composed of radiation-reactive preliminary stages of highly heat-resistant polymers.
Claim 11
Dependent Claim
156 words
In a method for producing relief structures comprised of double lacquer layers on substrates which already contain relief structures for integrated semiconductor circuits wherein high-energy radiation, such as particulate or photon radiation, is utilized for structuring, the improvement comprising: applying said double lacquer layer to said substrate with a lower lacquer layer positioned directly on said substrate and an upper lacquer layer positioned on said lower lacquer layer; said lower lacquer layer being composed of a thermoplastic material which does not cross-link at relatively low radiation dosage rates and which is free of ##STR2## radicals; said upper lacquer layer being thinner relative to the thickness of said lower lacquer layer by at least a factor of 2 and being comprised of a highly sensitive negative lacquer material; generating desired relief structures in said upper negative lacquer layer; and removing those portions of said lower lacquer layer which are not covered by said upper negative lacquer layer.
Claim 12
Dependent Claim
156 words
In a method for producing relief structures comprised of double lacquer layers on substrates which already contain relief structures for integrated semiconductor circuits wherein high-energy radiation, such as particulate or photon radiation, is utilized for structuring, the improvement comprising: applying said double lacquer layer to said substrate with a lower lacquer layer positioned directly on said substrate and an upper lacquer layer positioned on said lower lacquer layer; said lower lacquer layer being composed of a thermoplastic material which does not cross-link at relatively low radiation dosage rates and which is free of ##STR2## radicals; said upper lacquer layer being thinner relative to the thickness of said lower lacquer layer by at least a factor of 2 and being comprised of a highly sensitive negative lacquer material; generating desired relief structures in said upper negative lacquer layer; and removing those portions of said lower lacquer layer which are not covered by said upper negative lacquer layer.
Claim 13
Dependent Claim
45 words
In a method as defined in claim 10 wherein said upper negative lacquer layer is applied at a layer thickness ranging from about 0.1 through 1.0 μm and said lower lacquer layer is applied in a layer thickness ranging from about 0.2 through 3.0 μm.
Claim 14
Dependent Claim
66 words
In a method as defined in claim 10 wherein generating desired relief structures in said upper negative lacquer layer includes applying a negative lacquer mask onto said upper negative lacquer layer prior to exposure to radiation; and removing those portions of said lower lacquer layer which are not covered by said mask substantially simultaneously with development of the non-irradiated areas of said upper negative lacquer layer.
Claim 15
Dependent Claim
55 words
In a method as defined in claim 10 wherein said non-irradiated areas of said negative lacquer layer are removed by a developer selected from the group consisting of methyl ethyl ketone, methyl isobutyl ketone, a mixture of methy ethyl ketone and ethanol or isopropanol and a mixture of methyl isobutyl ketone and ethanol or isopropanol.
Claim 16
Dependent Claim
67 words
In a method as defined in claim 10 wherein said lower lacquer layer is composed of material selected from the group consisting of polyphenyleneoxide; polyethersulfone; polycarbonate; polymethacrylimide; novolak/diazochinone mixtures; polyolefinsulfones; polystyrolsulfones; polyalkylmethacrylates; copolymers and methylmethacrylate with a material selected from the group consisting of α--Cl-- acrylates, α-- CN--acrylates and methacrylnitrile; copolymers of methacrylate with fluoridated ester compounds; polybenzylmethacrylate; polymethylisopropenyl ketones; polyisobutylenes and copolymers thereof; and α-cyanoethylacrylate-α-amidoethylacrylate copolymers.
Claim 17
Dependent Claim
24 words
In a method as defined in claim 14 wherein said polyolefin sulfones are selected from the group consisting of polybutene-1-sulfone and cyclic polyolefin sulfone.
Claim 18
Dependent Claim
13 words
In a method as defined in claim 14 wherein said polyalkylmethacrylate is polymethylmethacrylate.
Claim 19
Dependent Claim
77 words
In a method as defined in claim 10 wherein said upper negative lacquer layer is composed of a material selected from the group consisting of glycidyl methacryalate; copolymers of glycidyl methacryalate (glycidyl acrylate) and a material selected from the group consisting of styrol, ethyl acrylate, opoxied butadiene, isoprene, polyacrylamide, polyvinylchloride, polysiloxane, a cyclic polyisoprene/diazide mixture (KTFR), polystyrol, polyvinylcarbazol, a halogenated polystyrol, polyvinylcarbazol, chlormethylated polystyrol, a cyclic polyisoprene/diazide mixture (KMER) methylmethacrylate-ethyl acrylate-glycidymethacrylate-terpolymer, partially esterified with 2-methacrylic acid (CER).
Claim 20
Dependent Claim
24 words
In a method as defined in claim 10 wherein said upper negative lacquer layer is composed of radiation-reactive preliminary stages of high heat-resistant polymers.
References Cited (Backward Citations)
US4004044A
Cited
US4024293A
Cited
US4268601A
Cited
US4204009A
Cited
US4202914A
Cited
US4287297A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-09-19 | 1987-03-21 | 1987-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-09-19 | 1991-03-21 | 1991-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-09-19 | 1995-03-21 | 1995-09-20 | $7700.00 | Window Closed / Lapsed |