Burls with altered surface topography for holding an object in lithography applications
US11270906B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 4, 2018 |
| Grant date | Mar 8, 2022 |
| Priority date | — |
| Expiry date | Oct 4, 2038 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/68757
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Various burl designs for holding an object in a lithographic apparatus are described. A lithographic apparatus includes an illumination system, a first support structure, a second support structure, and a projection system. The illumination system is designed to receive radiation and to direct the radiation towards a patterning device that forms patterned radiation. The first support structure is designed to support the patterning device on the first support structure. The second support structure has a plurality of burls and is designed to support the substrate on the plurality of burls. A topography of a top surface of each of the plurality of burls is not substantially flat, such that a contact area between the substrate and each of the plurality of burls is reduced. The projection system is designed to receive the patterned radiation and to direct the patterned radiation towards the substrate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.