In an embodiment, an apparatus includes an energy source, a support platform for holding a wafer, an optical path extending from the energy source to the support platform, and a photomask aligned such that a patterned major surface of the photomask is parallel to the force of gravity, where the optical path passes through the photomask, where the patterned major surface of the photomask is perpendicular to a topmost surface of the support platform.

A reflector comprising a hollow body having an interior surface defining a passage through the hollow body, the interior surface having at least one optical surface part configured to reflect radiation and a supporter surface part, wherein the optical surface part has a predetermined optical power and the supporter surface part does not have the predetermined optical power. The reflector is made by providing an axially symmetric mandrel; shaping a part of the circumferential surface of the mandrel to form at least one inverse optical surface part that is not rotationally symmetric about the axis of the mandrel; forming a reflector body around the mandrel; and releasing the reflector body from the mandrel whereby the reflector body has an optical surface defined by the inverse optical surface part and a supporter surface part defined by the rest of the outer surface of the mandrel.

In one example, an apparatus includes an extreme ultraviolet illumination source and an illuminator. The extreme ultraviolet illumination source is arranged to generate a beam of extreme ultraviolet illumination to pattern a resist layer on a substrate. The illuminator is arranged to direct the beam of extreme ultraviolet illumination onto a surface of a photomask. In one example, the illuminator includes a field facet mirror and a pupil facet mirror. The field facet mirror includes a first plurality of facets arranged to split the beam of extreme ultraviolet illumination into a plurality of light channels. The pupil facet mirror includes a second plurality of facets arranged to direct the plurality of light channels onto the surface of the photomask. The distribution of the second plurality of facets is denser at a periphery of the pupil facet mirror than at a center of the pupil facet mirror.

An extreme ultraviolet (EUV) source includes a collector associated with the vessel. The extreme ultraviolet (EUV) source includes a plurality of vanes along walls of the vessel. Each vane includes a stacked vane segment, and the stacked vane segments for each vane are stacked in a direction of drainage of tin (Sn) in the vessel. The EUV source includes a thermal control system comprising a plurality of independently controllable heating elements, where a heating element is configured to provide localized control for heating of a vane segment of the stacked vane segments.

Some implementations described herein provide techniques and apparatuses for inspecting interior surfaces of a vessel of a radiation source for an accumulation of a target material. An inspection tool, including a laser-scanning system and a motor system supported by an elongated supported member, may be inserted into the vessel to generate an accurate three-dimensional profile of the interior surfaces. Use of the inspection tool is efficient, with short setup and scan times that substantially reduce a duration associated with evaluating the interior surfaces of the vessel for the accumulation.

A radiation source for an EUV lithography apparatus is disclosed. The radiation source comprises a chamber comprising a plasma formation region, a radiation collector arranged in the chamber and configured to collect radiation emitted at the plasma formation region and to direct the collected radiation towards an intermediate focus region, and a radiation conduit disposed between the radiation collector and the intermediate focus region. The radiation conduit comprises at least one outlet on an inner surface of a wall of the radiation conduit for directing a protective gas flow, and at least one guide portion extending from the inner surface of the wall of the radiation conduit and configured to redirect the protective gas flow. Also disclosed is a method of reducing debris and/or vapor deposition in the radiation conduit by providing a protective gas flow to the at least one outlet of the radiation conduit.

In accordance with some embodiments, a lithography method in semiconductor manufacturing is provided. The lithography method includes transmitting a main pulse laser to a zone of excitation through a first optic assembly. The lithography method further includes supplying a coolant to the first optic assembly and detecting a temperature of the coolant with a use of at least one sensor. The lithography method also includes adjusting a heat transfer rate between the coolant and the first optic assembly based on the temperature of the first optic assembly. In addition, the lithography method includes generating a droplet of a target material into the zone of excitation. The lithography method further includes exciting the droplet of the target material into plasma with the main pulse laser in the zone of excitation.

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.

In an embodiment, a method includes: heating a byproduct transport ring of an extreme ultraviolet source, the byproduct transport ring disposed beneath vanes of the extreme ultraviolet source; after heating the byproduct transport ring for a first duration, heating the vanes; after heating the vanes, cooling the vanes; and after cooling the vanes for a second duration, cooling the byproduct transport ring.

An extreme ultraviolet light generation system includes a chamber, a target supply unit supplying a target substance to a plasma generation region including a first point in the chamber, a window allowing pulse laser light with which the target substance is irradiated to pass therethrough, an EUV light concentrating mirror concentrating extreme ultraviolet light generated at the first point on a second point, a planar mirror arranged on an optical path of the extreme ultraviolet light reflected by the EUV light concentrating mirror and between the first and second points, an actuator causing the second point to be switched between a first position and a second position, a connection portion connectable to an external apparatus, a first EUV measurement unit on which the extreme ultraviolet light having passed through the second position is incident, and a processor controlling the actuator based on a signal from the external apparatus.