A metal reuse system for an extreme ultra violet (EUV) radiation source apparatus includes a first metal collector for collecting metal from vanes of the EUV radiation source apparatus, a first metal storage coupled to the first metal collector via a first conduit, a metal droplet generator coupled to the first metal storage via a second conduit, and a first metal filtration device disposed on either one of the first conduit and the second conduit.

The invention relates to a droplet dispensing device (4) comprising a reservoir (9) for containing a liquid medium (10), an outlet (11) for dispensing droplets of said liquid medium (10) from said reservoir (9), an actuation means (12) for generating and transmitting a mechanical oscillation at an excitation frequency, and a resonant structure comprising a piston (15) coupled to said actuation means (12) for transmitting said mechanical oscillation to the liquid medium (10) contained in said reservoir (9) such that droplets are formed from said liquid medium (10), wherein a resonance frequency of said resonant structure is sufficiently close to said excitation frequency, such that resonance occurs.

The invention further relates to a UV or X-ray light source, comprising a droplet dispensing device (4) according to the invention, and a method for providing a stream, in particular a monodisperse stream, of droplets by means of the droplet dispensing device (4).

A method for monitoring a shock wave in an extreme ultraviolet light source includes irradiating a target droplet in the extreme ultraviolet light source apparatus of an extreme ultraviolet lithography tool with ionizing radiation to generate a plasma and to detect a shock wave generated by the plasma. One or more operating parameters of the extreme ultraviolet light source is adjusted based on the detected shock wave.

An amplified optical beam is provided to a region that receives a target including target material, an interaction between the amplified optical beam and the target converting at least some of the target material from a first form to a second form to form a light-emitting plasma; first data comprising information related to the amplified optical beam is accessed; second data comprising information related to the light-emitting plasma is accessed; and an amount of the target material converted from the first form to the second form is determined. The determination is based on at least the first data and the second data, and the second form of the target material is less dense than the first form of the target material.

Methods, devices, and systems for protecting a vacuum environment from leakage are provided. The devices include an optical component for gas-tight closure of the vacuum environment, a retention device configured to retain the optical component and including a cooling region separated from the vacuum environment in a gas-tight manner and configured to receive a cooling medium to cool the optical component, a first part-region of the optical component being arranged in the cooling region, and a reduced-pressure region configured to have a reduced pressure and separated in a gas-tight manner from the vacuum environment and from the cooling region, a second part-region of the optical component being arranged in the reduced-pressure region, and a detector configured to detect a leakage in the optical component when the cooling medium flows from the cooling region into at least one of the reduced-pressure region or the vacuum environment.

An EUV light generation device generates EUV light stably. The EUV light generation device may include a chamber in which extreme ultraviolet light is generated when a target is irradiated with laser light in a predetermined region inside the chamber, a target supply device configured to output the target to the predetermined region in the chamber to thereby supply the target to the predetermined region, and a target recovery apparatus configured to recover the target output from the target supply device and not irradiated with the laser light. The target recovery apparatus may include a receiver disposed to be inclined with respect to a trajectory of the target output from the target supply device, the receiver being configured to receive the target by allowing the target not irradiated with the laser light to collide with the receiver, and an excitation device configured to vibrate the receiver.

A first target is provided to an interior of a vacuum chamber, a first light beam is directed toward the first target to form a first plasma from target material of the first target, the first plasma being associated with a directional flux of particles and radiation emitted from the first target along a first emission direction, the first emission direction being determined by a position of the first target; a second target is provided to the interior of the vacuum chamber; and a second light beam is directed toward the second target to form a second plasma from target material of the second target, the second plasma being associated with a directional flux of particles and radiation emitted from the second target along a second emission direction, the second emission direction being determined by a position of the second target, the first and second emission directions being different.

A device and method are disclosed in which gas is caused to flow parallel to a flow of source material to form a gas shroud. The gas shroud may protect flow of source material from being disrupted by a cross flow of gas. The gas shroud may also limit heating of a physical shroud through which the source material passes and limit accumulation of source material on the physical shroud by deforming a plasma bubble formed during irradiation of the source material so that the plasma bubble does not come too near the physical shroud. A device and method are also disclosed for establishing an additional transverse flow of gas so that the gas shroud does not cause source material contamination of an optic used to collect light generated during irradiation of the source material.

A target supply device according to a first aspect of the present disclosure is configured to supply a metal target in a plasma generation region and may include a tank configured to house the metal target, a filter having been subjected to a dehydration process, the filter being configured to suppress passage of particles in the metal target housed in the tank, and a nozzle provided with a nozzle hole configured to eject the metal target that has passed through the filter.

A deoxidation system for purifying target material for an EUV light source includes a furnace having a central region and a heater for heating the central region in a uniform manner. A vessel is inserted in the central region of the furnace, and a crucible is disposed within the vessel. A closure device covers an open end of the vessel to form a seal having vacuum and pressure capability. The system also includes a gas input tube, a gas exhaust tube, and a vacuum port. A gas supply network is coupled in flow communication with an end of the gas input tube and a gas supply network is coupled in flow communication with an end of the gas exhaust tube. A vacuum network is coupled in flow communication with one end of the vacuum port. A method and apparatus for purifying target material also are described.