Lithographic apparatus and position sensor
US7830495B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 10, 2007 |
| Grant date | Nov 9, 2010 |
| Priority date | — |
| Expiry date | Nov 8, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70775
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A lithographic apparatus having a stationary magnet motor to drive a support such as a substrate support or a patterning device support, may be provided with a measurement system to measure a position of the support in question, e.g., to provide a safety system to prevent a collision of the support with another part. The measurement system may be configured to measure a magnetic field strength of an alternating magnetic field generated by the magnet assembly of the stationary magnet motor, and/or measure generation of eddy currents in a metallic layer shielding the magnet assembly in combination with an inductance measurement of an electromagnet generating the alternating magnetic field causing the eddy currents, and/or measure light using an optical position sensitive sensor such as a CCD metric or linear photodiode positioned in a light plane emitted by an emitter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.