Lithographic projection apparatus, a grating module, a sensor module, a method of measuring wave front aberrations
US6650399B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 12, 2002 |
| Grant date | Nov 18, 2003 |
| Priority date | — |
| Expiry date | Feb 12, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/706
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A lithographic projection apparatus including an illumination system; a support structure for holding a mask; a substrate table for holding a substrate; a projection system for projecting a pattern onto a target portion of the substrate; and an interferometric measurement system for measuring wave front aberrations of the projection system, characterized in that the interferometric measurement system including: a grating, featuring a grating pattern in a grating plane, said grating being movable into and out of the projection beam, such that the grating plane is substantially coincident with said object plane; a pinhole, featuring a pinhole pattern in a pinhole plane and arranged in a pinhole plate, said pinhole being movable into and out of the projection beam, such that the pinhole plane is substantially coincident with a plane downstream of the projection system and optically conjugate to said object plane, and a detector with a detector surface substantially coincident with a detection plane, said detection plane located downstream of the pinhole at a location where a spatial distribution of the electric field amplitude of the projection beam is substantially a Fourier transfor…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.