A target apparatus (300) for an extreme ultraviolet (EUV) light source includes a target generator, a sensor module (130), and a target generator controller (325). The target generator includes a reservoir (115) configured to contain target material (114) that produces EUV light in a plasma state and a nozzle structure (117) in fluid communication with the reservoir. The target generator defines an opening (119) in the nozzle structure through which the target material received from the reservoir is released. The sensor module is configured to: detect an aspect relating to target material released from the opening as the target material travels along a trajectory toward a target space (112), and produce a one-dimensional signal from the detected aspect. The target generator controller is in communication with the sensor module and the target generator, and is configured to modify characteristics of the target material based on an analysis of the one-dimensional signal.

A target droplet source for an extreme ultraviolet (EUV) source includes a droplet generator configured to generate target droplets of a given material. The droplet generator includes a nozzle configured to supply the target droplets in a space enclosed by a chamber. The target droplet source further includes a sleeve disposed in the chamber distal to the nozzle. The sleeve is configured to provide a path for the target droplets in the chamber.

In a method of generating extreme ultraviolet (EUV) radiation in a semiconductor manufacturing system one or more streams of a gas is directed, through one or more gas outlets mounted over a rim of a collector mirror of an EUV radiation source, to generate a flow of the gas over a surface of the collector mirror. The one or more flow rates of the one or more streams of the gas are adjusted to reduce an amount of metal debris deposited on the surface of the collector mirror.

An extreme ultraviolet light generation apparatus includes a chamber, a target supply unit configured to supply a target into the chamber, a prepulse laser configured to generate a diffusion target having a Gaussian distribution shape convex toward a travel direction of prepulse laser light by irradiating the target with the prepulse laser light, and a main pulse laser configured to generate extreme ultraviolet light by irradiating the diffusion target with main pulse laser light having an intensity distribution of a Gaussian distribution shape.

A light source includes a light generating chamber and a collector disposed in the light generating chamber. A target material generator configured to propel a quantity of target material toward an irradiation region is disposed in front of a reflective surface of the collector. A plurality of photodetector modules is disposed external to the light generating chamber, with each of the photodetector modules being directed toward the irradiation region. A plurality of tubes is disposed between a corresponding photodetector module and the irradiation region. Each tube has a centerline directed toward the irradiation region, and each tube has a roughened inner surface. The surface roughness of the roughened inner surface is sufficient to cause grazing incidences of light to be eliminated rather than to be reflected off the roughened inner surface. A method of generating light and a method of measuring light energy also are described.

A light source apparatus according to the present embodiment includes: a target holding unit including a holding region configured to hold a target material that generates light by excitation light being provided; a rotary shaft configured to support the target holding unit; and an axial rotation drive unit that is connected to the rotary shaft and configured to rotate, the target holding unit around a central axis of the rotary shaft, wherein the target holding unit is rotated by a predetermined target rotational angular velocity, and the target holding unit has a mass such that a critical angular velocity during rotation is equal to or lower than 85% of the target rotational angular velocity.

A target apparatus for an extreme ultraviolet (EUV) light source includes a target generator, a sensor module, and a target generator controller. The target generator includes a reservoir configured to contain target material that produces EUV light in a plasma state and a nozzle structure in fluid communication with the reservoir. The target generator defines an opening in the nozzle structure through which the target material received from the reservoir is released. The sensor module is configured to: detect an aspect relating to target material released from the opening as the target material travels along a trajectory toward a target space, and produce a one-dimensional signal from the detected aspect. The target generator controller is in communication with the sensor module and the target generator, and is configured to modify characteristics of the target material based on an analysis of the one-dimensional signal.

An extreme ultraviolet light generation system, generating extreme ultraviolet light by irradiating a target substance with laser light, includes a tank storing the target substance in a liquid state, a nozzle outputting the target substance stored in the tank, a piezoelectric element applying vibration to the target substance to be output from the nozzle to generate droplets of the target substance, a droplet detection device detecting a time interval of passage of the droplets output from the nozzle, and at least one processor. The processor acquires a first value of a vibration parameter relating to the vibration of the piezoelectric element, acquires a variation of the time interval corresponding to each of a plurality of values including the first value of the vibration parameter, and generates the droplets using a second value with which the variation of the time interval is smaller than that with the first value.

Methods and apparatuses for a lithography exposure process are described. The method includes irradiating a target droplet with a laser beam to create an extreme ultraviolet (EUV) light. The methods utilized and the apparatuses include two or more collectors for collecting the generated EUV light and reflecting the collected EUV light to a focal point of one of the collectors. In some embodiments, one of the two collectors includes a ring-shaped collector.

A method includes irradiating a target droplet in an extreme ultraviolet (EUV) light source of an extreme ultraviolet lithography tool with non-ionizing light from a droplet illumination module. The method further includes detecting light reflected and/or scattered by the target droplet, and performing particle image velocimetry, based on the detected light, to determine a velocity of the target droplet. The method also includes adjusting a time delay between a generation of the target droplet and a generation of an excitation laser beam based on the velocity of the target droplet.