An apparatus for reducing hydrogen permeation of a mask is provided when generating extreme ultraviolet (EUV) radiation. The apparatus includes a mask stage configured to hold the mask, a hydrogen dispensing nozzle configured to eject hydrogen below the mask, and a trajectory correcting assembly. The trajectory correcting assembly includes a correcting nozzle and a gas flow detector. The correcting nozzle is configured to dispense at least one flow adjusting gas to adjust a trajectory of the hydrogen away from the mask to reduce hydrogen permeation at an edge of the mask. The gas flow detector is configured to measure a variation of an airflow of the hydrogen adjusted by the at least one flow adjusting gas.

The present invention provides an exposure apparatus that exposes a substrate, comprising: an optical system configured to emit, in a first direction, light for exposing the substrate; a first supplier configured to supply a gas into a chamber where the optical system is arranged; and a second supplier configured to supply a gas to an optical path space where the light from the optical system passes through, wherein the second supplier includes a gas blower including a blowing port from which a gas is blown out in a second direction, and the guide member configured to guide the gas blown out from the blowing port to the optical path space, and the guide member includes a plate member extended on a side of the first direction of the blowing port so as to be arranged along the second direction.

Systems for cleaning optical surfaces of overlay inspection systems are disclosed. In particular, systems for optical-path coupling of light for in-situ photochemical cleaning in projection imaging systems are disclosed. A system for cleaning optical surfaces of overlay inspection systems includes a first illumination source, a detector, a set of illumination optics, and a set of imaging optics. In some embodiments, the system may include at least one of a second illumination source and a third illumination source, each of which may be configured to cause or aid the removal of contaminants from one or more optical surfaces of the system.

The invention relates to a device for measuring a substrate for semiconductor lithography with a reference interferometer for ascertaining the change in the ambient conditions, wherein the reference interferometer comprises a means for changing the optical path length of a measurement section of the reference interferometer, wherein the means is configured to bring about a change in the refractive index.

Furthermore, the invention relates to a method for correcting cyclic error components of a reference interferometer, wherein the reference interferometer comprises a means for changing the optical path length of a measurement section of the reference interferometer, comprising the following method steps: starting up the reference interferometer, continuously detecting measurement values of the reference interferometer, changing the optical path length of the measurement section of the reference interferometer until a path length change of at least one quarter of the wavelength of the reference interferometer is detected, determining the cyclic errors on the basis of the continuously detected measurement values of the reference interferometer, and correcting the current measurement values ascertained by the reference interferometer on the basis of the cyclic errors ascertained.

An apparatus for generating a laminar flow includes an injection nozzle and a suction nozzle. The injection nozzle and the suction nozzle are operable to form the laminar flow for blocking particles from contacting a proximate surface of an object. The injection nozzle includes a main outlet to blow out the laminar flow and is configured to generate a Coanda flow along an external surface of the injection nozzle. The suction nozzle is configured to provide a gas pressure gradient for the laminar flow.

A photolithography system utilizes tin droplets to generate extreme ultraviolet radiation for photolithography. The photolithography system irradiates the droplets with a laser. The droplets become a plasma and emit extreme ultraviolet radiation. The photolithography system senses contamination of a collector mirror by the tin droplets and adjusts the flow of a buffer fluid to reduce the contamination.

A stop, such as a numerical aperture stop, obscuration stop or false-light stop, for a lithography apparatus, includes a light-transmissive aperture and a stop element, in which or at which the aperture is provided. The stop element is opaque and fluid-permeable outside the aperture.

A method includes the following steps. A wafer is disposed on a wafer-mounting surface of a wafer holder that is disposed in a chamber. The wafer-mounting surface is in parallel with a gravity direction. A gas is flown from a gas source to vacuum sealing device. An inductive coil wrapping around a vacuum sealing device excites the gas into plasma. The plasma is injected to the wafer.

An exposure device has a cylindrical peripheral wall member. The peripheral wall member forms a processing space in which a substrate is storable and has an upper opening and a lower opening. Further, a light emitter is provided in an upper portion of the peripheral wall member to close the upper opening. A lower lid member that is provided to be movable in an up-and-down direction and configured to be capable of closing and opening the lower opening is provided below the peripheral wall member. The atmosphere in the processing space is replaced with an inert gas with the substrate stored in the processing space and the lower opening closed by the lower lid member. In this state, vacuum ultraviolet rays are emitted to the substrate from the light emitter, and the substrate is exposed.

Extreme ultraviolet light source systems may include a chamber including a condensing mirror and having an intermediate focus, by which extreme ultraviolet light reflected from the condensing mirror is emitted along a first optical path, a blocking plate that may be on the chamber so as to intersect the first optical path and may include an opening through which the extreme ultraviolet light is emitted, a transparent cover on the blocking plate so as to cover the opening, a nozzle that may be between the chamber and the blocking plate so that an end portion faces the intermediate focus and may spray a first gas in a direction intersecting the first optical path, and an exhaust pipe between the chamber and the blocking plate so as to face the end portion of the nozzle.