Abstract: A radiation system includes a contamination barrier configured to permit radiation from a radiation source to pass through and to capture debris coming from the radiation source. The contamination barrier includes a plurality of lamellas. The surface of the lamellas includes a material. The radiation system also includes a collector configured to collect radiation from the contamination barrier. An optical surface of the collector includes a material that is the same as the material of the surface of the lamellas.

Abstract: A radiation system includes a contamination barrier configured to permit radiation from a radiation source to pass through and to capture debris coming from the radiation source. The contamination barrier includes a plurality of lamellas. The surface of the lamellas includes a material. The radiation system also includes a collector configured to collect radiation from the contamination barrier. An optical surface of the collector includes a material that is the same as the material of the surface of the lamellas.

Abstract: A contamination barrier configured to permit radiation from a radiation source to pass through and to capture debris from the radiation source. The contamination barrier includes a support structure, a plurality of plate members arranged on the support structure and extending in a radial direction from an axis of the support structure, and a shield configured to block at least part of the support structure from being hit by radiation or debris from the radiation source.

Abstract: A contamination barrier configured to permit radiation from a radiation source to pass through and to capture debris from the radiation source. The contamination barrier includes a support structure, a plurality of plate members arranged on the support structure and extending in a radial direction from an axis of the support structure, and a shield configured to block at least part of the support structure from being hit by radiation or debris from the radiation source.

Abstract: A contamination barrier that passes through radiation from a radiation source and captures debris coming from the radiation source is disclosed. The contamination barrier includes an inner ring, an outer ring, and a plurality of lamellas. The lamellas extend in a radial direction from a main axis, and each of the lamellas is positioned in a respective plane that include the main axis. At least one outer end of each of the lamellas is slidably connected to at least one of the inner and outer ring.

Abstract: A grinding machine (1) for grinding a workpiece (40) comprises the following components: a cup wheel (10) having an annular grinding surface (11); a disc-shaped electrode (60), which is positioned in the vicinity of at least a portion of the grinding surface (11) such that a dressing area (75) is obtained in which a relatively small gap is present between the electrode (60) and the grinding surface (11), feed means (70) for feeding electrolyte to the dressing area (75); and a generator (20) for generating an electric current between the grinding surface (11) and the electrode (60), via the electrolyte. The electrode (60) is movable with respect to the dressing area (75), so that contamination of the electrode (60), which normally occurs as a result of the dressing process, is continuously removed. Consequently, the quality of the dressing process is maintained at a high level.

Abstract: In a lithographic projection apparatus, a slider is provided for motion of the substrate table or mask table. The slider is supported on a gas-bearing and separates a region at atmospheric pressure from a vacuum space region. A differential pressure pump is provided to maintain the pressure difference in the presence of the gas-bearing. A pressure compensation vessel is provided on top of the slider and also contains a vacuum. Over most of the area of the slider, the pressure on its opposed first and second sides is the same and so deformation of the slider is avoided. The sidewalls of the pressure compensation vessel transmit the external gas pressure to the slider such that they are in line with the forces of the gas-bearing.

Abstract: A bearing for use in a vacuum chamber comprises a gas bearing discharging pressurised gas into a gap between two members to maintain a predetermined separation between those members.

Abstract: A long-stroke movement is fed-through into a vacuum chamber by providing a sliding seal over an aperture in the vacuum chamber wall. The object to be moved, which may be a mask or wafer table in a lithographic apparatus, within the vacuum chamber is connected to or mounted on the sliding seal and moved by movement of the sliding seal. The sliding seal may be a plate, a bowl or a labyrinth of interleaved plates.

Abstract: A contamination barrier that passes through radiation from a radiation source and captures debris coming from the radiation source is disclosed. The contamination barrier includes an inner ring, an outer ring, and a plurality of lamellas. The lamellas extend in a radial direction from a main axis, and each of the lamellas is positioned in a respective plane that include the main axis. At least one outer end of each of the lamellas is slidably connected to at least one of the inner and outer ring.

Abstract: A reference frame provided in a vacuum chamber is supported by support pillars extending through and isolated from the vacuum chamber walls to isolate the reference frame from vibrations in the vacuum chamber. The gap between the support pillar and the vacuum chamber wall may be sealed by a low-stiffness seal. The low stiffness seal may be a three part seal allowing relative motion in six-degrees of freedom.

Abstract: A lithographic projection apparatus comprises a vacuum chamber having a wall enclosing at least one of first and second object tables, the or each object table within the vacuum chamber being connected to positioning means for positioning the object table with respect to a projection system of the apparatus. The positioning means is provided with a pneumatic gravity compensator comprising a piston associated with the object table; a gas-filled pressure chamber, the gas in the pressure chamber acting on the movable member to at least partially counteract the weight of the object table; a gas bearing; and evacuating means for evacuating gas escaping through a gap between the movable member and a bearing surface of a cylindrical housing towards the vacuum chamber. A partially flexible rod connects the piston to the object table.

Abstract: A bearing for use in a vacuum chamber comprises a gas bearing discharging pressurised gas into a gap between two members to maintain a predetermined separation between those members.

Abstract: A lithographic projection apparatus comprises a vacuum chamber having a wall enclosing at least one of first and second object tables, the or each object table within the vacuum chamber being connected to positioning means for positioning the object table with respect to a projection system of the apparatus. The positioning means is provided with a pneumatic gravity compensator comprising a piston associated with the object table; a gas-filled pressure chamber, the gas in the pressure chamber acting on the movable member to at least partially counteract the weight of the object table; a gas bearing; and evacuating means for evacuating gas escaping through a gap between the movable member and a bearing surface of a cylindrical housing towards the vacuum chamber. A partially flexible rod connects the piston to the object table.

Abstract: An object table is supported in a vacuum chamber by an elongate beam or beams extending through elongate slots in opposite walls of the vacuum chamber. Displacement of the beam in two orthogonal directions is achieved by displacing the beam laterally and longitudinally. The elongate slots are sealed by sliding plates supported by a gas bearing. The beam is driven longitudinally by linear motors acting against between a balance mass and the beam. The beam is driven laterally by linear motors acting between a balance mass and the sliding plates. The two balance masses may be separate or combined.

Abstract: A bearing for use in a vacuum chamber comprises a gas bearing discharging pressurised gas into a gap between two members to maintain a predetermined separation between those members. To avoid the gas forming the gas bearing being an unacceptable leak into the vacuum chamber, a vacuum pump is provided between the vacuum chamber and the gas bearing.

Abstract: A lithographic projection apparatus comprises a vacuum chamber having a wall enclosing at least one of first and second object tables, the or each object table within the vacuum chamber being connected to positioning means for positioning the object table with respect to a projection system of the apparatus. The positioning means is provided with a pneumatic gravity compensator comprising a piston associated with the object table; a gas-filled pressure chamber, the gas in the pressure chamber acting on the movable member to at least partially counteract the weight of the object table; a gas bearing; and evacuating means for evacuating gas escaping through a gap between the movable member and a bearing surface of a cylindrical housing towards the vacuum chamber. A partially flexible rod connects the piston to the object table.

Abstract: A lithographic apparatus for step-and-scan operation has a three stage structure for the wafer stage. During step-and-scan operation, the long-stroke stage is moved steadily along the row or column of dies to be exposed sequentially. An intermediate scanning stage moves in a figure-of-eight motion relative to the long-stroke stage so that the net movement of the fine stage, which is carried by the scanning stage, is a meander path.

Abstract: In a lithographic projection apparatus, a slider is provided for motion of the substrate table or mask table. The slider is supported on a gas-bearing and separates a region at atmospheric pressure from a vacuum space region. A differential pressure pump is provided to maintain the pressure difference in the presence of the gas-bearing. A pressure compensation vessel is provided on top of the slider and also contains a vacuum. Over most of the area of the slider, the pressure on its opposed first and second sides is the same and so deformation of the slider is avoided. The sidewalls of the pressure compensation vessel transmit the external gas pressure to the slider such that they are in line with the forces of the gas-bearing.

Abstract: A long-stroke movement is fed-through into a vacuum chamber by providing a sliding seal over an aperture in the vacuum chamber wall. The object to be moved, which may be a mask or wafer table in a lithographic apparatus, within the vacuum chamber is connected to or mounted on the sliding seal and moved by movement of the sliding seal. The sliding seal may be a plate, a bowl or a labyrinth of interleaved plates.