Focusing and leveling device
US10809059B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 27, 2017 |
| Grant date | Oct 20, 2020 |
| Priority date | — |
| Expiry date | Nov 27, 2037 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70258
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A focusing and leveling device calculates an amount of defocus and/or tilt of a substrate and includes an illumination unit, projection-side mark plate with projection-side slit mark, projection-side imaging group, deflection prism, beam splitter, detection unit and signal processing unit. A light beam emitted from the illumination unit passes through the projection-side mark plate and is trimmed into a probe beam directed by the projection-side imaging group onto a substrate surface. The prism deflects the probe beam reflected by the surface of the substrate for a first time so that it is incident on the substrate surface and reflected for a second time onto the projection-side imaging group. The beam splitter directs the probe beam that travelled through the projection-side imaging group onto the detection unit. The signal processing unit calculates the amount of defocus and/or tilt based on a measurement spot detected by the detection unit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.