Contrast-enhancing agent for photolithography
US4925770A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Dec 14, 1988 |
| Grant date | May 15, 1990 |
| Priority date | — |
| Expiry date | Dec 14, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/091
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The invention provides a novel contrast-enhancing agent for photolithography which is used as an overcoating on a positive-working photoresist layer for enhancing the contrast of the photoresist in a low-contrast exposure to light. The composition comprises, in addition to a watersoluble polymer, e.g., poly(vinyl alcohol), poly(vinyl pyrroilidone) and pullulan, as the binder, a specific photo-bleachable organic compound having, in a molecule, at least one nitrogen-containing heterocyclic aromatic structure represented by the general formula ##STR1## in which Z is a divalent group to form the heterocyclic aromatic ring with the nitrogen atom, X is an anionic group of monovalency and n is a positive integer of, e.g., 1 or 2.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.