Immersion lithographic apparatus including a pressure sensor to measure pressure of the immersion liquid and a device manufacturing method

A device manufacturing method, comprising:

• projecting a patterned beam of radiation onto a substrate held by a substrate table through an immersion liquid provided in a space adjacent the substrate using a lithographic apparatus;
• measuring the pressure of the immersion liquid in the space using a pressure sensor associated with an immersion fluid flow which flows out of the space through an opening in an opening surface;
• and
• controlling a force applied to the substrate table by a positioner responsive to the pressure, the positioner adapted to move the substrate table to position the substrate table relative to a projection system that is adapted to project the pattern beam of radiation, the force being controlled based on a pressure signal,
• wherein the pressure sensor is located in an extraction conduit configured to extract immersion liquid from the space through the opening, and
• wherein the apparatus comprises an additional pressure sensor that is provided in the opening surface.

An immersion lithographic apparatus comprising:

• a projection system arranged to project an image onto a substrate held by a substrate table through an immersion liquid provided in a space between the projection system and the substrate;
• an extraction conduit configured to extract immersion liquid from the space, through an inlet formed in a surface, along with a gas in a two-phase flow, wherein the surface faces a substrate, a substrate table or both;
• and
• a pressure sensor located in the inlet of the extraction conduit and configured to generate a signal indication of the pressure of the immersion liquid in the space, and
• an additional pressure sensor that is provided in the surface.