Metal ion reduction in novolak resin using an ion exchange catalyst in a polar solvent and photoresists compositions therefrom
US5521052A · kind A · utility
25Cited by
19References
9Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 30, 1994 |
| Grant date | May 28, 1996 |
| Priority date | — |
| Expiry date | Dec 30, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/948
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The present invention provides methods for producing water insoluble, aqueous alkali soluble, film forming novolak resins having an extremely low level of metal ions, utilizing treated anion and cation exchange resins. A method is also provided for producing photoresist composition having a very low level of metal ions from such novolak resin and for producing semiconductor devices using such photoresist compositions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.