Debris mitigation device with rotating foil trap and drive assembly

US8338797B2 · kind B2 · utility

Assignee

• KONINKLIJKE PHILIPS ELECTRONICS NV · NL

Inventors

• Guenther Hans Derra · Aachen, DE
• Michael Schaaf · Solingen, DE

Key dates

• Filing date: Feb 25, 2009
• Grant date: Dec 25, 2012
• Expiry date: Jul 15, 2029

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F7/70808
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

The present invention relates to a debris mitigation device for use with a radiation source (2) generating optical radiation, in particular extreme ultraviolet radiation (EUV) or soft x-rays, and emitting undesired substances and/or particles which can deposit on optical surfaces in a radiation path of said radiation source (2), and to a corresponding drive assembly. The debris mitigation device comprises at least one rotating foil trap (5) and the drive assembly. The drive assembly comprises a driving motor (14) and a driving axis (10), to which the rotating foil trap (5) is fixed. The driving motor (14) and bearings (13) supporting the driving axis (10) are enclosed in a casing (20) having an aperture for the driving axis (10) and at least one outlet opening (21) for a sealing gas. The outlet opening (21) is connectable to a pump for pumping out the sealing gas. The aperture is designed to define a gap (23) between the driving axis (10) and the casing (20), wherein said gap (23) is connected to a supply pipe (19) for supplying the sealing gas through said gap (23) into said casing (20). The proposed debris mitigation device allows the use of conventional driving motors and oiled …