Abstract:
A device is arranged to measure a quantity relating to radiation. The device includes a sensor configured to measure the quantity, a screen arranged to protect the sensor from incoming particles emitted from a source configured to emit extreme ultraviolet radiation, and a mirror configured to redirect extreme ultraviolet radiation emitted by the source, past the screen, to the sensor.
Abstract:
A method for the protection of an optical element of a lithographic apparatus is disclosed. A deposition gas comprising SnH4 is provided to the surface of the optical element to deposit a Sn cap layer on the surface of the optical element. In this way, a Sn cap layer is deliberately provided on the optical element, which may protect the optical element during lithographic processing from debris from a (Sn) plasma source. During or after lithographic processing, the (deteriorated) cap layer may be repaired by providing a hydrogen radical containing gas and/or a SnH4 containing gas. Additionally or alternatively, the (deteriorated) cap layer may be removed and a new cap layer provided by providing the deposition gas comprising SnH4.
Abstract:
A radiation system for generating a beam of radiation that defines an optical axis is provided. The radiation system includes a plasma produced discharge source for generating EUV radiation. The discharge source includes a pair of electrodes constructed and arranged to be provided with a voltage difference, and a system for producing a plasma between the pair of electrodes so as to provide a discharge in the plasma between the electrodes. The radiation system also includes a debris catching shield for catching debris from the electrodes. The debris catching shield is constructed and arranged to shield the electrodes from a line of sight provided in a predetermined spherical angle relative the optical axis, and to provide an aperture to a central area between the electrodes in the line of sight.
Abstract:
An optical sensor apparatus for use in an extreme ultraviolet lithographic system is disclosed. The apparatus includes an optical sensor comprising a sensor surface and a removal mechanism configured to remove debris from the sensor surface. Accordingly, dose and/or contamination measurements may be carried out conveniently for the lithographic system.
Abstract:
A source module for use in a lithographic apparatus is constructed to generate extreme ultra violet (EUV) and secondary radiation, and includes a buffer gas configured to cooperate with a source of the EUV radiation. The buffer gas has at least 50% transmission for the EUV radiation and at least 70% absorption for the secondary radiation.
Abstract:
According to an aspect of the present invention, a spectral purity filter includes an aperture, the aperture being arranged to diffract a first wavelength of radiation and to allow at least a portion of a second wavelength of radiation to be transmitted through the aperture, the second wavelength of radiation being shorter than the first wavelength of radiation, wherein the aperture has a diameter greater than 20 μm.
Abstract:
A method of forming a spectral purity filter having a plurality of apertures configured to transmit extreme ultraviolet radiation and suppress transmission of a second type of radiation, in which trenches are formed in a base material in a pattern corresponding to the walls to be formed between the apertures. The trenches are filled with a grid material to form walls of the grid material, and the base material is selectively removed until the grid material is exposed and forms the spaces between the walls of the grid material for the apertures.
Abstract:
A lithographic apparatus includes a plasma source that includes a vessel configured to enclose a plasma formation site, an optical device configured to transfer optical radiation to or from the vessel, and a reflector arranged in an optical path between the optical device and the plasma formation site source. The reflector is configured to reflect the optical radiation between the optical device and the plasma formation site. The reflector is formed, in operation, as a molten metal mirror.
Abstract:
A metal component (262M, 300M) is designed for use in an EUV lithography apparatus, for example as a spectral purity filter (260) or a heating element (300) in a hydrogen radical generator. An exposed surface of the metal is treated (262P, 300P) to inhibit the formation of an oxide of said metal in an air environment prior to operation. This prevents contamination of optical components by subsequent evaporation of the oxide during operation of the component at elevated temperatures.
Abstract:
A spectral purity filter is configured to allow transmission therethrough of extreme ultraviolet (EUV) radiation and to refract or reflect non-EUV secondary radiation. The spectral purity filter may be part of a source module and/or a lithographic apparatus.