An extreme ultraviolet light source apparatus includes a cathode, an anode, a power supply, a first support structure for supporting the cathode, and a second support structure for supporting the anode. The power supply causes discharge between the cathode and anode for generating a plasma that emits extreme ultraviolet light. The cathode and the anode are connected to the first and second rotational shafts made of metal, respectively. The first support structure has a first support wall portion and a first tubular portion surrounding the first shaft. The second support structure has a second support wall portion and a second tubular portion surrounding the second shaft. The first and second support wall portions overlap each other. The first support wall portion has a through-hole through which the second tubular portion is inserted, or the second support wall portion has a through-hole through which the first tubular portion is inserted.

A method for using an extreme ultraviolet radiation source is provided. The method includes performing a lithography process using an extreme ultraviolet (EUV) radiation source; after the lithography processes, inserting an extraction tube into a vessel of the EUV radiation source; and cleaning a collector of the EUV radiation source by using the extraction tube.

A method of controlling a droplet illumination module/droplet detection module system of an extreme ultraviolet (EUV) radiation source includes irradiating a target droplet with light from a droplet illumination module and detecting light reflected and/or scattered by the target droplet. The method includes determining whether an intensity of the detected light is within an acceptable range. In response to determining that the intensity of the detected light is not within the acceptable range, a parameter of the droplet illumination module is automatically adjusted to set the intensity of the detected light within the acceptable range.

A radiation source arrangement causes interaction between pump radiation (340) and a gaseous medium (406) to generate EUV or soft x-ray radiation by higher harmonic generation (HHG). The operating condition of the radiation source arrangement is monitored by detecting (420/430) third radiation (422) resulting from an interaction between condition sensing radiation and the medium. The condition sensing radiation (740) may be the same as the first radiation or it may be separately applied. The third radiation may be for example a portion of the condition sensing radiation that is reflected or scattered by a vacuum-gas boundary, or it may be lower harmonics of the HHG process, or fluorescence, or scattered. The sensor may include one or more image detectors so that spatial distribution of intensity and/or the angular distribution of the third radiation may be analyzed. Feedback control based on the determined operating condition stabilizes operation of the HHG source.

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.

An extreme ultraviolet (EUV) photolithography system generates EUV light by irradiating droplets with a laser. The system includes a droplet generator with a nozzle and a piezoelectric structure coupled to the nozzle. The generator outputs groups of droplets. A control system applies a voltage waveform to the piezoelectric structure while the nozzle outputs the group of droplets. The waveform causes the droplets of the group to have a spread of velocities that results in the droplets coalescing into a single droplet prior to being irradiated by the laser.

The present disclosure is directed to a modularized vessel droplet generator assembly (MGDVA) including a droplet generator assembly (DGA). Under a normal operation, the liquid fuel moves along an operation pathway extending through the DGA to eject or discharge the liquid fuel (e.g., liquid tin) from a nozzle of the DGA into a vacuum chamber. The liquid fuel in the vacuum chamber is then exposed to a laser generating an extreme ultra-violet (EUV) light. Under a service operation, the operation pathway is closed and a service pathway extending through the DGA is opened. A gas is introduced into the service pathway forming a gas-liquid interface between the gas and the liquid fuel. The gas-liquid interface is driven to an isolation valve directly adjacent to the DGA. In other words, the gas pushes back the liquid fuel to the isolation valve. Once the gas-liquid interface reaches the isolation valve, the isolation valve is closed isolating the DGA from the liquid fuel.

A method includes following steps. A photoresist-coated substrate is received to an extreme ultraviolet (EUV) tool. An EUV radiation is directed from a radiation source onto the photoresist-coated substrate, wherein the EUV radiation is generated by an excitation laser hitting a plurality of target droplets ejected from a first droplet generator. The first droplet generator is replaced with a second droplet generator at a temperature not lower than about 150° C.

Disclosed is an apparatus and a method in which off-droplet measurements instead of on-droplet measurements of prepulse energy are used for pulse energy control. Prepulse energy is measured during an off-droplet nonexposure period and controlled to a prepulse energy setpoint. The prepulse energy can then be controlled open-loop to the prepulse energy setpoint during on-droplet periods. This effectively decouples the EUV dose control loop from the prepulse energy control loop and avoids negative side effects of coupling such loops, for example, loss of the part of the dose adjustment range available to the dose controller.

A target supply device may include a tank configured to store a target substance, a pressure adjuster configured to adjust a pressure in the tank, a filter configured to filter the target substance in the tank, a nozzle configured to output a droplet of the target substance having passed through the filter, a droplet detector configured to detect outputting of the droplet from the nozzle, and a processor configured to control the pressure adjuster so that a pressure-increasing speed of the pressure in the tank is higher after detection of outputting of the droplet than before detection of outputting of the droplet, during a period in which the pressure in the tank is increased to a target pressure from a pressure at which outputting of the droplet is detected by the droplet detector for the first time after installation of the target supply device.