Lithographic apparatus and device manufacturing method

摘要

Various types of pressure regulating devices are disclosed to reduce a pressure gradient in a liquid supply system of a lithographic apparatus, the liquid supply system having a liquid confinement structure configured to at least partially confine a liquid between a projection system and a substrate table of the lithographic apparatus. A high pressure gradient may cause particulate contamination in the liquid supply system and/or liquid confinement structure. A pressure gradient can be reduced by, for example, the use of slow switching in one or more valves, a bleed flow around or through one or more valves, diversion of liquid to a drain rather than or in addition to switching a valve off, a pressure regulator or flow restrictor to prevent shock waves, and a buffer volume/damper to compensate for pressure fluctuation.

主权项

1. A lithographic apparatus, comprising:
a substrate table constructed to hold a substrate; a projection system configured to project a radiation beam onto a target portion of the substrate; and a liquid supply system comprising a liquid confinement structure configured to at least partially confine a liquid in a space between the projection system and the substrate table; and a pressure regulating device configured to reduce a pressure fluctuation in liquid being supplied in or to the liquid confinement structure, the pressure regulating device comprising a bleed flow device for use with a valve in the liquid supply system, the bleed flow device configured to create a bleed flow of liquid in the liquid supply system when the valve is switched to an off position.