Metal ion reduction in the raw materials and using a Lewis base to control molecular weight of novolak resin to be used in positive photoresists
US5476750A · kind A · utility
26Cited by
15References
7Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 29, 1992 |
| Grant date | Dec 19, 1995 |
| Priority date | — |
| Expiry date | Dec 29, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/0236
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The present invention provides methods for producing water insoluble, aqueous alkali soluble novolak resins having a very low level of metal ions and a substantially consistent molecular weight. A method is also provided for producing photoresist composition from such novolak resins and for producing semiconductor devices using such photoresist compositions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.