Abstract: A gas gauge has a gas delivery tube arranged to determine a distance to an object. The gas delivery tube includes a gas conduit through which a suitable measurement gas is supplied. The measurement gas leaves the gas delivery tube under pressure via an outlet and impinges on the object in an interaction area, wherein a pressure of a recoiled gas is measured by a pressure detector. A gas having a low atomic number may be used. The pressure sensor may include a membrane positioned in the gas delivery tube at least partially enveloping the gas conduit at or near the gas outlet. The pressure sensor may include a membrane disk arranged about the gas conduit. The pressure sensor may include a suitable plurality of pressure elements arranged in a substantially common plane and which may be spaced apart yet enveloping the gas conduit.

Abstract: A module for producing extreme ultraviolet radiation includes a supply configured to supply droplets of an ignition material to a predetermined target ignition position and a laser arranged to be focused on the predetermined target ignition position and to produce a plasma by hitting such a droplet which is located at the predetermined target ignition position in order to change the droplet into an extreme ultraviolet producing plasma. Also, the module includes a collector mirror having a mirror surface constructed and arranged to reflect the radiation in order to focus the radiation on a focal point. A fluid supply is constructed and arranged to form a gas flow flowing away from the mirror surface in a direction transverse with respect to the mirror surface in order to mitigate particle debris produced by the plasma.

Abstract: A lithographic apparatus is arranged to project a pattern from a patterning device onto a substrate is disclosed. The lithographic apparatus includes an illumination system and an outlet connected to a pumping system to pump away gas from between an inner wall and outer wall of the illumination system or, if a radiation source is present, between the inner wall of the illumination system and an inner wall of the radiation source.

Abstract: A lithographic apparatus includes a projection system configured to project a patterned beam of radiation onto a target portion of a substrate. The projection system includes a first gas-conditioned sub-environment and a second gas-conditioned sub-environment. The apparatus includes a gas control unit configured to control the feeding of conditioned gas into the first sub-environment and into the second sub-environment via the first sub-environment so as to prevent contamination from the second sub-environment to the first sub-environment. The apparatus includes a gate configured to leak the conditioned gas at a rate from the second sub-environment to ambient atmosphere, and a detector configured to detect at least one property of the second gas-conditioned environment.

Abstract: A lithographic apparatus includes an illumination system for providing beam of radiation, and a support structure for supporting a patterning device. The patterning device imparts the beam of radiation with a pattern. The apparatus also includes a substrate table for holding a substrate, a projection system for projecting the patterned beam onto a target portion of the substrate, and a gas supply system for supplying a purge gas including oxygen to a plurality of spaces in the apparatus. The gas supply system is arranged so that the purge gas supplied to each of the plurality of spaces is a premixed purge gas mixture composed by the gas supply system for each of the plurality of spaces on the basis of a predetermined relationship that relates a desired amount of oxygen in the premixed purge gas mixture to the respective space to which that premixed purge gas mixture is supplied.

Abstract: A lithographic apparatus is disclosed. The apparatus includes a projection system configured to project a patterned radiation beam onto a target portion of a substrate. The projection system includes a housing and a plurality of optical elements arranged in the housing. The apparatus also includes an inlet for feeding conditioned gas to the housing and a gas exhaust for exhausting the conditioned gas from the housing for providing a gas conditioned environment in the housing. At least one gate is provided for providing communication of the gas conditioned environment with ambient atmosphere. The gate is arranged to provide a predetermined leakage of the conditioned gas to the ambient atmosphere.