An extreme ultraviolet light generator includes a collector including a first focus and a second focus, a droplet feeder configured to provide a source droplet toward the first focus of the collector, a laser generator configured to irradiate a laser toward the first focus of the collector, an airflow controller between the first focus and the second focus of the collector, the airflow controller having a ring shape, and the airflow controller including at least one slit, and a first part and a second part hinged to each other, and a control gas feeder configured to provide a control gas towards the at least one slit of the airflow controller.

Some implementations described herein provide a dual-feedback control system for laser beam targeting in a lithography system such as an EUV lithography system. In addition to using feedback from a high-frequency quad-cell sensor to adjust a target position of the pre-pulse laser beam based on a first portion of a phase of a wavefront of the pre-pulse laser beam, the dual-feedback control system uses feedback from a low-frequency camera sensor to adjust the target position of the pre-pulse laser beam based on a second portion of the phase of the wavefront.

A storage and drainage mechanism includes a storage vessel, a drainage section, and a temperature controller. The storage vessel stores a stored material containing metal of plasma raw material at a temperature at which the stored material is in a liquid-phase state. The drainage section includes a drain pipe including an inlet through which the stored material flows in, and an outlet through which the stored material drains away, the drain pipe being communicated with an interior of the storage vessel, and a temperature control element that adjusts a temperature of the drain pipe. The temperature controller controls the temperature control element to switch the temperature of the drain pipe in a manner that the stored material in the drain pipe is in either a liquid-phase state or a solid-phase state.

The stability of operations of an EUV light generating apparatus is improved. A droplet detector may include: a light source unit configured to emit illuminating light onto a droplet, which is output into a chamber and generate extreme ultraviolet light when irradiated with a laser beam; a light receiving unit configured to receive the illuminating light and to detect changes in light intensities; and a timing determining circuit configured to output a droplet detection signal that indicates that the droplet has been detected at a predetermined position within the chamber, based on a first timing at which the light intensity of the illuminating light decreases due to the droplet being irradiated therewith and a second timing at which the light intensity of the illuminating light increases.

A vessel (16) for an EUV radiation source, the vessel comprising a first opening (30) for accessing an interior (32) of the vessel, a first access member (34) configured to allow or prevent access to the interior of the vessel through the first opening, a second opening (36) for accessing the interior of the vessel, the second opening being arranged in the first access member and a second access member (38) arranged on the first access member and configured to allow or prevent access to the interior of the vessel through the second opening.

A circulation mechanism includes a storage section, a supply pipe, a collection pipe, a circulation drive section, and a protective member. The storage section accommodates liquid metal. The supply pipe supplies the liquid metal accommodated in the storage section to a target mechanism. The collection pipe is communicated with the storage section and collects the liquid metal that has been drained away from the target mechanism into the storage section. The circulation drive section allows the liquid metal accommodated in the storage section to move to the supply pipe, and thus circulates the liquid metal to and from the target mechanism. The protective member is disposed to cover a portion of an inner wall of the collection pipe, the portion corresponding to a position at which the liquid metal flowing through the collection pipe collides with the liquid metal accommodated in the storage section.

A light source for EUV radiation is provided. The light source includes a target droplet generator, a laser generator, and a controller. The target droplet generator is configured to provide target droplets to a source vessel. The laser generator is configured to provide a plurality of first laser pulses according to a control signal to irradiate the target droplets in the source vessel to generate plasma as the EUV radiation. The controller is configured to provide the control signal according to the temperature of the source vessel and droplet positions of the target droplets. When the temperature of the source vessel exceeds a temperature threshold value and a standard deviation of the droplet positions of the target droplets exceeds a first standard deviation threshold value, the controller is configured to provide the control signal to the laser generator, so as to stop providing the first laser pulses.

A collector mirror for an extreme ultraviolet (EUV) light generator includes a first mirror in a vessel, the vessel being configured to receive a material and a laser beam for generating the EUV light, a second mirror surrounding the first mirror, and a detachable third mirror between the first mirror and the second mirror, the third mirror having an inner diameter that is not smaller than an outer diameter of the first mirror, and an outer diameter that is not larger than an inner diameter of the second mirror.

An extreme ultraviolet light (EUV) source apparatus includes a light source part for generating a plasma that emits EUV light; a first vacuum housing in which the light source part is located; a second vacuum housing arranged between the first vacuum housing and a utilizing apparatus in which the EUV light is utilized; and a debris trap located inside the second vacuum housing for deflecting debris particles emitted from the plasma, whereby the debris particles do not ingress into the utilizing apparatus. Between the first and second vacuum housings, there is provided a window through which the EUV light emitted from the light source part passes from the first vacuum housing to the second vacuum housing. A wall of the second vacuum housing has a through-hole and a window that is configured to allow the EUV light to pass from the second vacuum housing to the utilizing apparatus.

An extreme ultra violet (EUV) light source apparatus includes a metal droplet generator, a collector mirror, an excitation laser inlet port for receiving an excitation laser, a first mirror configured to reflect the excitation laser that passes through a zone of excitation, and a second mirror configured to reflect the excitation laser reflected by the first mirror.