Gas gauge, lithographic apparatus and device manufacturing method
US8220315B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 30, 2009 |
| Grant date | Jul 17, 2012 |
| Priority date | — |
| Expiry date | Mar 8, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7057
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A gas gauge has a gas delivery tube arranged to determine a distance to an object. The gas delivery tube includes a gas conduit through which a suitable measurement gas is supplied. The measurement gas leaves the gas delivery tube under pressure via an outlet and impinges on the object in an interaction area, wherein a pressure of a recoiled gas is measured by a pressure detector. A gas having a low atomic number may be used. The pressure sensor may include a membrane positioned in the gas delivery tube at least partially enveloping the gas conduit at or near the gas outlet. The pressure sensor may include a membrane disk arranged about the gas conduit. The pressure sensor may include a suitable plurality of pressure elements arranged in a substantially common plane and which may be spaced apart yet enveloping the gas conduit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.