Extreme ultraviolet reticle protection using gas flow thermophoresis
US7030959B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jul 23, 2004 |
| Grant date | Apr 18, 2006 |
| Priority date | — |
| Expiry date | Sep 17, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70933
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Methods and apparatus for using a flow of a relatively cool gas to establish a temperature gradient between a reticle and a reticle shield to reduce particle contamination on the reticle are disclosed. According to one aspect of the present invention, an apparatus that reduces particle contamination on a surface of an object includes a plate and a gas supply. The plate is positioned in proximity to the object such that the plate, which has a second temperature, and the object, which has a first temperature, are substantially separated by a space. The gas supply supplies a gas flow into the space. The gas has a third temperature that is lower than both the first temperature and the second temperature. The gas cooperates with the plate and the object to create a temperature gradient and, hence, a thermophoretic force that conveys particles in the space away from the object.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.