Abstract: A radiation source for generating EUV from a stream of molten fuel droplets by LPP (Laser Produced Plasma) or (Dual Laser Plasma) has a fuel droplet generator arranged to provide a stream of droplets of fuel and at least one laser configured to vaporize at least some of the droplets of fuel, whereby radiation is generated. The fuel droplet generator has a nozzle, a feed chamber, and a reservoir, with a pumping device arranged to supply a flow of fuel in molten state from the reservoir through the feed chamber and out of the nozzle as a stream of droplets. The feed chamber has an outer face in contact with a drive cavity filled with a liquid, and the liquid is driven to oscillate by a vibrator with the oscillation transmissible to the molten fuel in the feed chamber from the outer face of the feed chamber through the liquid.

Abstract: A position measurements system to measure a position of a movable object with respect to another object includes two or more one dimensional (1D) encoder heads mounted on one of the movable object and the other object and each capable of emitting a measurement beam along a measurement direction, one or more reference targets mounted on the other of the movable object and the other object, each reference target including a planar surface with a grid or grating to cooperate with the two or more one dimensional (1D) encoder heads, and a processor to calculate a position of the object on the basis of outputs of the two or more 1D encoder heads, wherein the measurement direction of each of the two or more 1D encoder heads is non-perpendicular to the planar surface of the respective reference target.

Abstract: In a lithographic apparatus, a localized area of the substrate surface under a projection system is immersed in liquid. The height of a liquid supply system above the surface of the substrate can be varied using actuators. A control system uses feedforward or feedback control with input of the surface height of the substrate to maintain the liquid supply system at a predetermined height above the surface of the substrate.

Abstract: In a lithographic apparatus, a localized area of the substrate surface under a projection system is immersed in liquid. The height of a liquid supply system above the surface of the substrate can be varied using actuators. A control system uses feedforward or feedback control with input of the surface height of the substrate to maintain the liquid supply system at a predetermined height above the surface of the substrate.

Abstract: An immersion lithographic projection apparatus is disclosed in which liquid is provided between a projection system of the apparatus and a substrate. The use of both liquidphobic and liquidphilic layers on various elements of the apparatus is provided to help prevent formation of bubbles in the liquid and to help reduce residue on the elements after being in contact with the liquid.

Abstract: A lithographic apparatus is disclosed that includes an encoder type sensor system configured to measure a position of a substrate table of the lithographic apparatus relative to a reference structure. The encoder type sensor system includes an encoder sensor head and an encoder sensor target and the lithographic apparatus comprises a recess to accommodate the encoder sensor target.

Abstract: A lithographic apparatus includes a source configured to generate a radiation beam comprising desired radiation and undesired radiation using a plasma, an illumination system configured to condition the radiation beam and to receive hydrogen gas during operation of the lithographic apparatus, and a support structure constructed to hold a patterning device. The patterning device is capable of imparting the radiation beam with a pattern in its cross-section to form a patterned radiation beam. A substrate table is constructed to hold a substrate, and a projection system is configured to project the patterned radiation beam onto a target portion of the substrate. The lithographic apparatus is configured such that the radiation beam on entering the projection system includes at least 50% of the undesired radiation that is generated by the plasma and includes wavelengths of radiation that interact with the hydrogen gas to generate hydrogen radicals.

Abstract: A lithographic apparatus for patterning a beam of radiation and projecting it onto a substrate, comprising at least two spectral purity filters configured to reduce the intensity of radiation in the beam of radiation in at least one undesirable range of radiation wavelength, wherein the two spectral purity filters are provided with different radiation filtering structures from each other.

Abstract: A method of removing liquid from a substrate supported on a substrate table and from a gap between the substrate and the substrate table includes: providing a liquid removal device with at least one outlet connected to an under pressure source, the outlet forming an elongated extractor of a predetermined geometry; relatively moving the substrate table and the liquid removal device such that the extractor is adapted to pass over all of the substrate and gap and such that substantially at any given time any local part of the extractor at the edge of a non-dried portion of the gap has, in a plane, its local tangent orientated at an angle of between about 35° and 90° to the local tangent of the gap.

Abstract: A lithographic projection apparatus is disclosed for use with an immersion liquid positioned between the projection system and a substrate. Several methods and mechanism are disclosed to protect components of the projection system, substrate table and a liquid confinement system. These include providing a protective coating on a final element of the projection system as well as providing one or more sacrificial bodies upstream of the components. A two component final optical element of CaF2 is also disclosed.

Abstract: Liquid is supplied to a space between the projection system and the substrate by an inlet. In an embodiment, an overflow region removes liquid above a given level. The overflow region may be arranged above the inlet and thus the liquid may be constantly refreshed and the pressure in the liquid may remain substantially constant.

Abstract: A lithographic projection apparatus is disclosed in which a liquid supply system provides a liquid between the projection system and the substrate. An active drying station is provided to actively remove the liquid from the substrate W or other objects after immersion of all or part of a surface of the substrate W or other objects.

Abstract: An immersion lithographic projection apparatus is disclosed in which liquid is provided between a projection system of the apparatus and a substrate. The use of both liquidphobic and liquidphilic layers on various elements of the apparatus is provided to help prevent formation of bubbles in the liquid and to help reduce residue on the elements after being in contact with the liquid.

Abstract: In a lithographic projection apparatus, a liquid supply system maintains liquid in a space between the projection system and the substrate. The liquid supply system may further include a de-mineralizing unit, a distillation unit, a de-hydrocarbonating unit, a UV radiation source, and/or a filter configured to purify the liquid. A gas content reduction device may be provided to reduce a gas content of the liquid. A chemical may be added to the liquid using an adding device to inhibit lifeform growth and components of the liquid supply system may be made of a material which is non-transparent to visible light such that growth of lifeforms may be reduced.

Abstract: A lithographic apparatus includes a projection system, a fluid handling structure, a metrology device, and a recycling control device. The projection system is configured to project a patterned radiation beam onto a target portion of a substrate, the substrate being supported on a substrate table. The fluid handling structure is configured to provide an immersion fluid to a space between the projection system and the substrate and/or substrate table. The metrology device is configured to monitor a parameter of the immersion fluid. The recycling control device regulates a routing of the immersion fluid either to be reused by the fluid handling structure or to be reconditioned based on the quality of immersion fluid indicated by the metrology device.

Abstract: Disclosed is an electrostatic clamp apparatus (500) constructed to support a patterning device (505) of a lithographic apparatus, comprising a support structure against which said patterning device is supported, clamping electrodes (525) for providing a clamping force between the support structure and patterning device, and an array of capacitive sensors (660) operable to measure the shape of said patterning device.

Abstract: A radiation source is configured to produce extreme ultraviolet radiation. The radiation source includes a chamber in which, in use, a plasma is generated, and an evaporation surface configured to evaporate a material formed as a by-product from the plasma and that is emitted to the evaporation surface. A method for removing a by-product material in or from a plasma radiation source of a lithographic apparatus includes evaporating a material which, in use, is emitted to that surface from the plasma.

Abstract: An EUV radiation source includes a fuel supply configured to supply fuel to a plasma formation location. The fuel supply includes a nozzle configured to eject droplets of fuel, and a droplet accelerator configured to accelerate the fuel droplets. The EUV radiation source includes a laser radiation source configured to irradiate the fuel supplied by the fuel supply at the plasma formation location.

Abstract: In a lithographic projection apparatus, a structure surrounds a space between the projection system and a substrate table of the lithographic projection apparatus. A gas seal is formed between said structure and the surface of said substrate to contain liquid in the space.

Abstract: An immersion lithography apparatus includes a liquid supply system configured to supply a liquid to a space through which a beam of radiation passes, the liquid having an optical property that can be tuned by a tuner. The space may be located between the projection system and the substrate. The tuner is arranged to adjust one or more properties of the liquid such as the shape, composition, refractive index and/or absorptivity as a function of space and/or time in order to change the imaging performance of the lithography apparatus.