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US4330614A Expired / Lapsed US ⏱️ 0.0 years remaining

Process for forming a patterned resist mask

Assignee: International Business Machines Corp
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Filing: 1980-10-14
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Granted: 1982-05-18
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Expires: 2000-10-14
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Abstract

Abstract The performance of ethylene glycol alkylether developers, for positive methacrylate-methacrylic acid copolymer and terpolymer resists, is controlled by adding an organic complexing agent, such as citric acid, or a combination of a transition metal salt and a complexing agent, such as ammonium citrate, to the developer. The additives provide a consistent development rate, so that the maximum difference between the dissolution rates of the exposed and unexposed portions of the resist layer can be maintained, regardless of the developer purity.

Inventors

  • 👤 William A. Moyer
  • 👤 Robert L. Wood

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 23:54
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/26; G03F7/30; G03F7/32; G03F7/325

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 67 words
In a process for forming a patterned resist mask, in which a methacrylate polymer layer is formed on a substrate, patternwise exposed to radiation, and then contacted with an organic solvent developer to remove the exposed portions of the layer, the improvement which comprises, adding to said developer an organic complexing agent, wherein a transition metal ion is added in order to provide a tailored development rate.
Claim 2
Dependent Claim 67 words
In a process for forming a patterned resist mask, in which a methacrylate polymer layer is formed on a substrate, patternwise exposed to radiation, and then contacted with an organic solvent developer to remove the exposed portions of the layer, the improvement which comprises, adding to said developer an organic complexing agent, wherein a transition metal ion is added in order to provide a tailored development rate.
Claim 3
Dependent Claim 78 words
In a process for forming a patterned resist mask, in which a methacrylate polymer layer is formed on a substrate, patternwise exposed to radiation, and then contacted with an organic solvent developer to remove the exposed portions of the layer, the improvement which comprises, adding to said developer an organic complexing agent, wherein the polymer is a methyl methacrylate/methacrylic acid/methacrylic anhydride terpolymer, the developer is 2-ethoxyethanol, the complexing agent is citric acid and the amine is triethanol amine.
Claim 4
Dependent Claim 78 words
In a process for forming a patterned resist mask, in which a methacrylate polymer layer is formed on a substrate, patternwise exposed to radiation, and then contacted with an organic solvent developer to remove the exposed portions of the layer, the improvement which comprises, adding to said developer an organic complexing agent, wherein the polymer is a methyl methacrylate/methacrylic acid/methacrylic anhydride terpolymer, the developer is 2-ethoxyethanol, the complexing agent is citric acid and the amine is triethanol amine.

References Cited (Backward Citations)

US3475171A Cited
US3987215A Cited
US4130425A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1985-05-17 1985-11-16 1986-05-18 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1989-05-17 1989-11-16 1990-05-18 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1993-05-17 1993-11-16 1994-05-18 $7700.00 Window Closed / Lapsed

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