Method of forming pattern and projection aligner for carrying out the same
US4904569A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 15, 1988 |
| Grant date | Feb 27, 1990 |
| Priority date | — |
| Expiry date | Jan 15, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70858
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An area on a photoresist film which is formed on a substrate surface having a topography, is exposed a plurality of times in such a manner that the image plane of a mask pattern is formed at a plurality of positions which are spaced apart from a reference plane in the substrate in the direction of an optical axis, and then the photoresist film is developed to form a resist pattern. According to the above method, the effective focal depth of the projection aligner used is enhanced, and moreover the reduction of the image contrast at the photoresist film is made very small by the plural exposure operations. Accordingly, a fine pattern can be formed accurately on the substrate surface having the topography.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.