Lithographic Evaluation of Copolymers with Enhanced Dry Etch Resistance.
Abstract
Electron beam lithographic performance of copolymers of alpha methyl styrene with maleic anhydride (PMAAMS), and with methyl maleate (PMMAMS) has been evaluated. RIE rates have also been determined with the purpose of developing a resist system with both adequate sensitivity and dry etch resistance. Poly(alpha methyl styrene) has been shown to exhibit an RIE etch rate of half that of PMMA(1), but its sensitivity is poor due to its low G-scission (G(s)) of 0.25 scissions/100 ev(2,3). However, the alternating copolymer of AMS with maleic anhydride (PMAAMS) exhibits a G(s) similar to that of PMMA (G(s) = 0.62 - 0.64)3,4. These findings were surprising because it had previously been expected that maleic anhydride would crosslink upon irradiation. The present work indicated negligible crosslinking. the G(s) of the AMS copolymer with the monomethyl ester of maleic anhydride was previously reported as 1.6(3), but the present work with both gamma and electron irridation indicates higher Gs values by a factor of almost 2. Keywords: Alpha methyl styrene; Methyl maleate copolymer; Microlithography; Electron beam resist; Maleic anhydride copolymer; Copolymers; Lithography; Electron beams.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 17, 1987
- Accession Number
- ADA179457
Entities
People
- B. C. Dems
- G. G. Gifford
- J. M. Rosenblum
- S. K. Obendorf
- Y. M. Namaste
Organizations
- Cornell University School of Chemical and Biomolecular Engineering