Negative-Working Electron Beam Resist Based on Poly(methyl methacrylate)
Abstract
Blends of polymethylmethacrylate (PMMA) and dipentaerythritol pentaacrylate (DPEPA) respond to electron beam exposure as negative resists, with sensitivity that increases with increasing DPEPA concentration. Blends of 80 wt. % PMMA and 20 wt. % DPEPA exhibit an electron sensitivity of 4 microcoulombs/sq cm and a contrast gamma of 1.2. Resolution of 0.25 micrometers has been demonstrated with this blend without the use of non-solvent rinses or plasma de-scumming. This superior resolution for a negative electron resist is attributed to the small degree of swelling of the PMMA host polymer. Increasing the molecular weight of the PMMA component to 450,000 increases the sensitivity to 1 microcoulomb/sq cm improves the contrast to a gamma value of 2.3 without affecting resolution or sensitivity relative to the blends with low molecular weight PMMA.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 12, 1989
- Accession Number
- ADA207834
Entities
People
- B. C. Dems
- Francisco J. Medellı́n-Rodrı́guez
- S. K. Obendorf
- Y. M. Namastet
Organizations
- Cornell University School of Chemical and Biomolecular Engineering