Lithographic apparatus, reflective member and a method of irradiating the underside of a liquid supply system

摘要

A lithographic apparatus that includes a reflector configured to reflect a cleaning beam of radiation projected through a projection system onto an underside of a liquid retrieval system. The construction of the reflector is also described as is a method for irradiating the underside of a liquid supply system for use in cleaning.

主权项

1. A lithographic projection apparatus, comprising:
a projection system configured to project a beam of radiation onto a substrate; a substrate table configured to hold the substrate; a liquid retrieval system configured to retrieve liquid from a space between the projection system and the substrate table; a liquid supply system configured to provide a cleaning liquid, which is chemically different from said liquid, in contact with at least part of an underside of the liquid retrieval system to remove contamination present on said underside; and on a surface facing the projection system, a reflector configured to reflect a cleaning beam of radiation projected through the projection system onto the underside of the liquid retrieval system and through the cleaning liquid, the reflector having a surface receiving radiation from the projection system that is substantially co-planar with a surface, nearest the projection system, of the substrate when held by the substrate table, the reflector including a reflecting member configured to reflect substantially all radiation of the cleaning beam of radiation onto the underside of the liquid retrieval system.