Process for device fabrication using projection lithography and an apparatus therefor
US5561008A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 27, 1995 |
| Grant date | Oct 1, 1996 |
| Priority date | — |
| Expiry date | Jan 27, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/31791
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The invention is directed to a method and apparatus of projection lithography in which the contrast introduced into a radiation sensitive material caused by the proximity effect is effectively removed in a single exposure. Patterned radiation is transmitted through a lens system with at least one lens and a back focal plane filter. The back focal plane filter has at least two apertures, an image aperture and a proximity effect correction aperture. Patterned radiation is transmitted through the image aperture and introduces the desired image into the energy sensitive resist material. A portion of the inverse pattern radiation is transmitted through the proximity effect correction aperture and onto the energy sensitive resist material to effectively remove the contrast therein caused by the proximity effect.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.