Environmentally friendly removal of photoresists used in wet etchable polyimide processes
US6159666A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 8, 1999 |
| Grant date | Dec 12, 2000 |
| Priority date | — |
| Expiry date | Jan 8, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/425
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Normally, a positive photoresist is developed with an alkaline aqueous solution to form patterns, and is subsequently stripped with an organic solvent after the photoresist has served its function. Such strippers are relatively toxic and damaging to the environment, and cannot be handled by standard (community) waste-water treatment facilities. These strippers cannot be easily neutralized, and must be disposed of in a highly specialized and relatively expensive manner. The present invention provides a method of treating positive and negative photoresists during their usage as photo masks such that the photoresists may be removed by less toxic chemicals which can be readily neutralized and handled by conventional waste water treatment facilities.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.