Pneumatic support device with a controlled gas supply, and lithographic device provided with such a support device
US6144442A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jun 10, 1998 |
| Grant date | Nov 7, 2000 |
| Priority date | — |
| Expiry date | Jun 10, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70833
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
Support device (53) provided with a first part (69) and a second part (71) which is supported relative to the first part by means of a gas spring (73) having a pressure chamber (75). A gas supply (117), which compensates for gas leakage from the pressure chamber (75) during operation, is connected to an intermediate space (119) which is in communication with the pressure chamber (75) via a pneumatic restriction (121). The gas pressure present in the intermediate space (119) is held as constant as possible during operation by means of a control loop (123), to prevent transmission of pressure fluctuations which are present in the gas supply (117) to the pressure chamber (75) as much as possible. Such pressure fluctuations are undesirable in the pressure chamber because they cause mechanical vibrations in the second part of the support device and the device to be supported. The support device is used in a lithographic device for the support of a frame (39) with respect to a base (37), the frame (39) supporting a focusing unit (5).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.