Composition for eliminating microbridging in chemically amplified photoresists comprising a polymer blend of a poly(hydroxystyrene) and a copolymer made of hydroxystyrene and an acrylic monomer
US5547812A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 5, 1995 |
| Grant date | Aug 20, 1996 |
| Priority date | — |
| Expiry date | Jun 5, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S430/111
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Microbridge formation in chemically amplified negative tone photoresists based on poly(hydroxystyrene) (PHS) is avoided when the PHS is blended together with a co-polymer of PHS and an acrylic polymer such as poly(methyl methacrylate) (PMMA). The blend should include at least 10% by weight of the co-polymer. In operation, hydrogen bonding between the hydroxystyrene sub-units and the methacrylate sub-units decreases the availability of sites for crosslinking, and this reduction in crosslinking sites makes the blend less susceptible to formation of polymer resist microbridges. The invention is practicable with a polymers having a wide range of molecular weights (2000-50000 daltons), and development can be achieved using the industry standard 2.38 wt % trimethylammonium hydroxide (TMAH) developer without any adverse impact on the photoresist.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.