Patent ID: 7113259
Filing Date: 2006-09-26
Classification: G03F

Abstract:
1. An immersion system for a lithographic projection apparatus, the lithographic projection apparatus including a radiation system configured to provide a beam of radiation; a support configured to supporting a patterning device, the patterning device configured to pattern the beam according to a desired pattern; a substrate table configured to hold a substrate; and a projection system configured to project the patterned beam onto a target portion of the substrate, the immersion system comprising: a transparent plate positioned between an optical element of the projection system and the substrate; a first fluid supply configured to supply a first fluid having a first index of refraction to a first space between the substrate and the transparent plate; and a second fluid supply configured to supply a second fluid having a second index of refraction to a second space between the transparent plate and the optical element, wherein the first fluid supply is a first reservoir filled with the first fluid and the second fluid supply is a second reservoir filled with the second fluid and the second fluid is confined to the second reservoir by a gas seal, the gas seal including an inlet configured to introduce a gas to the second space and an outlet configured to extract gas from the second space.