Substrate holding apparatus for vertically holding a substrate in an exposure apparatus
US5253012A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 2, 1991 |
| Grant date | Oct 12, 1993 |
| Priority date | — |
| Expiry date | Oct 2, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/707
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A substrate holding apparatus for vertically holding a substrate to be exposed by radiation includes a substrate holding member for attracting a substrate by a magnetic force or vacuum and an engaging device for engaging the substrate on the substrate holding member. The engaging device is retractably supported by or fixed to the substrate holding member, and is engageable with or engages the substrate in such a manner that the engagement between the vertically held substrate and the engaging device is maintained even if the substrate holding member ceases to attract the substrate. Thus, dropping of the substrate by gravitation is prevented even if the substrate ceases to be attracted by the substrate holding member.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.