Synthesis and evaluation of cyclic olefin sulfone copolymers and terpolymers as electron beam resists

Journal Article · Tue Mar 01 00:00:00 EST 1977 · J. Appl. Polym. Sci.; (United States)

DOI:https://doi.org/10.1002/app.1977.070210309· OSTI ID:7215718

Gipstein, E; Moreau, W; Chiu, G; Need, III, O U

Poly(cyclopentene sulfone) (PCPS) and poly(bicycloheptene sulfone) (PBCHS) copolymers have been evaluated as potential positive electron beam resists which have good thermal properties and which show high sensitivity to ionizing radiation. It was found that thin copolymer films could be processed as resists but that films greater than 3000 A thick cracked in the solvents used to dissolve the radiation-exposed regions. Films from low molecular weight polymer fractions cracked less in solvents, but higher radiation doses were required to offset the reduced sensitivity. This resulted in the formation of intractable residues in the exposed regions which appear to be crosslinked polymer. Terpolymerization with ..cap alpha..-olefins such as butene-1 and cis-2-butene plasticized these films and reduced their tendency to crack in solvents. Poly(cyclopentene sulfone-co-butene-1 sulfone) films were found to have the best properties, and 1.25-..mu.. resist images could be etched in SiO/sub 2/ layers at an exposure dose of 4 x 10/sup -6/ C/cm/sup 2/ at 25 KV. However, one important limitation of this terpolymer was the low dissolution rate ratio between the exposed and unexposed regions. PBCHS block terpolymers containing methyl methacrylate (MMA) or methacrylic acid (MAA) were synthesized to improve the solubility in solvents and to incorporate the properties of methacrylates. PBCHS-MMA films cracked in solvents after irradiation; PBCHS-MAA polymers were too insoluble to form resist films.

• Research Organization: IBM Research Lab., San Jose, CA
• OSTI ID: 7215718
• Journal Information: J. Appl. Polym. Sci.; (United States), Vol. 21:3
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
42 ENGINEERING
CYCLOALKENES
CHEMICAL RADIATION EFFECTS
SYNTHESIS
SULFONES
CHEMICAL PROPERTIES
COPOLYMERS
ELECTRON BEAMS
FILMS
METHACRYLIC ACID
METHYL METHACRYLATE
OPTIMIZATION
THERMODYNAMIC PROPERTIES
ALKENES
BEAMS
CARBOXYLIC ACID ESTERS
CARBOXYLIC ACIDS
CHEMISTRY
ESTERS
HYDROCARBONS
LEPTON BEAMS
METHACRYLIC ACID ESTERS
MONOCARBOXYLIC ACIDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC POLYMERS
ORGANIC SULFUR COMPOUNDS
PARTICLE BEAMS
PHYSICAL PROPERTIES
POLYMERS
RADIATION CHEMISTRY
RADIATION EFFECTS
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360404 - Materials- Polymers & Plastics- Physical Properties- (-1987)
420800 - Engineering- Electronic Circuits & Devices- (-1989)