Patent ID: 7705962
Filing Date: 2010-04-27
Classification: G03F

Abstract:
1. A lithographic projection apparatus, comprising: a projection system arranged to project a patterned beam of radiation onto a substrate; and a liquid supply system arranged to supply liquid to a space between the projection system and the substrate, the liquid supply system comprising a liquid confinement structure configured to form a seal between its lower surface and the substrate to substantially contain the liquid in the space, wherein a recess having an opening in the lower surface has a port open to a first pressure source for extraction of liquid and/or gas and the same recess has a port open to a second pressure source, the first pressure source being at a lower pressure than the second pressure source such that there is a flow of gas toward the first pressure source from the second pressure source, the port open to the first pressure source and the port open to the second pressure source arranged at different radial distances in the lower surface of the liquid confinement structure and arranged at a distance further away from the substrate than the recess opening.