Proximity-type microlithography apparatus and method
US5891806A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 17, 1997 |
| Grant date | Apr 6, 1999 |
| Priority date | — |
| Expiry date | Apr 17, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/942
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Apparatus and methods are disclosed for increasing the illuminance at a mask used for proximity-type microlithography and for achieving increases in throughput. A mask defining a pattern is illuminated by an illumination optical system. The pattern is transferred to a workpiece separated from the mask by a prescribed standoff. The mask and workpiece can be relatively moved in a scan direction. With respect to the illumination optical system, the workpiece-side numerical aperture in a first direction on the plane of the mask is different from the workpiece-side numerical aperture in a second direction, perpendicular to the first direction, on the plane of the mask. A reflective-type relay optical system can be included that comprises first and second spherical mirrors that do not produce chromatic aberrations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.