Photographic element with diazo contrast enhancement layer and method of producing image in underlying photoresist layer of element
US4777111A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 23, 1987 |
| Grant date | Oct 11, 1988 |
| Priority date | — |
| Expiry date | Mar 23, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/091
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
This invention relates to a composition and method for enhancing the contrast of images of an underlying photolithographic layer. A photographic element, including a photoresist layer, is applied to a substrate. The photoresist layer contains a contrast-enhancing layer including at least one light-sensitive compound capable of producing acidic photoproducts upon exposure to actinic radiation, at least one indicator dye that changes color on exposure to acidic conditions and at least one polymeric binder soluble in water or weakly alkaline aqueous solutions. The photographic element is exposed to active radiation sufficient to cause photobleaching of the contrast enhancement layer and exposure of the photoresist layer. The photographic element is exposed to actinic radiation sufficient to cause photobleaching of the contrast enhancement layer and exposure of the photoresist layer. The photographic element is developed in an aqueous photoresist developer, whereby the contrast enhancement layer is stripped from the photoresist layer by the developer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.