A radiation source apparatus includes a vessel, a laser source, a collector, and a reflective mirror. The vessel has an exit aperture. The laser source is at one end of the vessel and configured to excite a target material to form a plasma. The collector is disposed in the vessel and configured to collect a radiation emitted by the plasma and to direct the collected radiation to the exit aperture of the vessel. The reflective mirror is in the vessel and configured to reflect the laser beam toward an edge of the vessel.

An extreme ultraviolet (EUV) light concentrating apparatus including a main body having a concave inner portion and configured to rotate, a tin generator configured to generate tin drops and spray the tin drops, a tin catcher configured to process the sprayed tin drops, a protective cover configured to block the tin drops from falling into the main body, and a rotation guide configured to rotate the main body may be provided.

A method and a system for generating intense, ultrashort pulses of XUV and soft X-ray radiation via high-order harmonic generation (HHG), the method comprising selecting a nonlinear solid target and a laser source; separating a beam from the laser source into a first laser beam and a second laser beam; focusing the first laser beam onto the nonlinear solid target, thereby generating a laser ablated plume; and compressing and frequency-doubling the second laser beam and directing a resulting second compressed and frequency-doubled laser beam to the laser ablated plume, thereby yielding high-order harmonic generation of radiation of photon energies in a range between 12 eV and 36 eV. A high-order harmonic source of radiation, comprising a nonlinear solid target; a laser source; a beam splitter separating a beam from the laser source into a first beam line and a second beam line; the first beam line comprising a first focusing unit directing a first, uncompressed, laser beam onto the nonlinear solid target, to generate a laser ablated plume; and the second beam line directing a second, compressed and frequency-doubled laser beam, to the laser ablated plume, yielding high-order harmonic generation of radiation of photon energies in a range between 12 eV and 36 eV.

A method and a system for generating intense, ultrashort pulses of XUV and soft X-ray radiation via high-order harmonic generation (HHG), the method comprising selecting a nonlinear solid target and a laser source; separating a beam from the laser source into a first laser beam and a second laser beam; focusing the first laser beam onto the nonlinear solid target, thereby generating a laser ablated plume; and compressing and frequency-doubling the second laser beam and directing a resulting second compressed and frequency-doubled laser beam to the laser ablated plume, thereby yielding high-order harmonic generation of radiation of photon energies in a range between 12 eV and 36 eV. A high-order harmonic source of radiation, comprising a nonlinear solid target; a laser source; a beam splitter separating a beam from the laser source into a first beam line and a second beam line; the first beam line comprising a first focusing unit directing a first, uncompressed, laser beam onto the nonlinear solid target, to generate a laser ablated plume; and the second beam line directing a second, compressed and frequency-doubled laser beam, to the laser ablated plume, yielding high-order harmonic generation of radiation of photon energies in a range between 12 eV and 36 eV.

A control system includes a plurality of pressure sensors, each to detect a pressure in a respective dynamic gas lock (DGL) nozzle control region of a plurality of DGL nozzle control regions. Each DGL nozzle control region includes one or more DGL nozzles. The control system includes a plurality of mass flow controllers (MFCs). Each MFC of the plurality of MFCs is to control a flow velocity in a respective DGL nozzle control region of the plurality of DGL nozzle control regions. The control system includes a controller to selectively cause one or more MFCs of the plurality of MFCs to adjust flow velocities in one or more DGL nozzle control regions of the plurality of DGL nozzle control regions based on pressures detected by the plurality of pressure sensors in DGL nozzle control regions of the plurality of DGL nozzle control regions.

Some implementations described herein provide techniques and apparatuses for an extreme ultraviolet (EUV) radiation source that includes a backsplash-prevention system to reduce, minimize, and/or prevent the formation of tin (Sn) build-up in a tunnel structure of a collector flow ring that might otherwise be caused by the accumulation of Sn satellites. This reduces backsplash of Sn onto a collector of the EUV radiation source, increases the operational life of the collector (e.g., by increasing the time duration between cleaning and/or replacement of the collector), reduces downtime of the EUV radiation source, and/or enables the performance of the EUV radiation source to be sustained for longer time durations (e.g., by reducing, minimizing, and/or preventing the rate of Sn contamination of the collector), among other examples.

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.

An EUV light generation apparatus includes a chamber; a prepulse laser outputting prepulse laser light; a main pulse laser outputting main pulse laser light; a combiner combining optical paths of the prepulse laser light and the main pulse laser light; a light concentrating unit concentrating, on the target, the prepulse laser light and the main pulse laser light having the optical paths combined; a stage changing a position of the light concentrating unit; a first actuator changing a travel direction of the main pulse laser light; an EUV light sensor detecting EUV energy; a laser energy sensor detecting pulse energy of the main pulse laser light; and an EUV light generation control unit controlling the stage so that temporal variation of the EUV energy decreases and controlling the first actuator so that a ratio of the EUV energy to the pulse energy increases.

A droplet generator for an extreme ultraviolet imaging tool includes a reservoir for a molten metal, and a nozzle having a first end connected to the reservoir and a second opposing end where molten metal droplets emerge from the nozzle. A gas inlet is connected to the nozzle, and an isolation valve is at the second end of the nozzle configured to seal the nozzle droplet generator from the ambient.

Example implementations described herein include a laser source and associated methods of operation that can balance or reduce uneven beam profile problem and even improve plasma heating efficiency to enhance conversion efficiency and intensity for extreme ultraviolet radiation generation. The laser source described herein generates an auxiliary laser beam to augment a pre-pulse laser beam and/or a main-pulse laser beam, such that uneven beam profiles may be corrected and/or compensated. This may improve an intensity of the laser source and also improve an energy distribution from the laser source to a droplet of a target material, effective to increase an overall operating efficiency of the laser source.