Apparatus and method for the improvement of illumination uniformity in photolithographic systems
US6262795A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 28, 1998 |
| Grant date | Jul 17, 2001 |
| Priority date | — |
| Expiry date | Aug 28, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70191
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An apparatus for forming a pattern in a photoresist material includes a light source to provide light for illuminating a portion of the photoresist material according to the pattern and a filter positioned in a path of the light. The filter includes a number of regions upon which a filtering material has been. The filtering material has a variable characteristic that is independently adjustable for each region to enhance the uniformity of the intensity of the light. Such characteristics include the thickness of the filtering material, the size of the portion of the region that is covered by the filtering material, or a voltage, current, electric field, or magnetic field applied to the filtering material of each region.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.