A laser irradiation method of irradiating, with a pulse laser beam, an irradiation object in which an impurity source film is formed on a semiconductor substrate includes: reading fluence per pulse of the pulse laser beam with which a rectangular irradiation region set on the irradiation object is irradiated and the number of irradiation pulses the irradiation region is irradiated, the fluence being equal to or larger than a threshold at or beyond which ablation potentially occurs to the impurity source film when the irradiation object is irradiated with pulses of the pulse laser beam in the irradiation pulse number and smaller than a threshold at or beyond which damage potentially occurs to the surface of the semiconductor substrate; calculating a scanning speed Vdx; and moving the irradiation object at the scanning speed Vdx relative to the irradiation region while irradiating the irradiation region with the pulse laser beam at the repetition frequency f.

A laser chamber apparatus may include a pipe, an inner electrode extending along a longitudinal direction of the pipe and disposed in a through hole in the pipe, an outer electrode including a contact plate extending along the longitudinal direction of the pipe and being in contact with an outer circumferential surface of the pipe and a ladder section formed of bar members each having one end connected to the contact plate and juxtaposed along a longitudinal direction of the contact plate, and a leaf spring extending along the longitudinal direction of the pipe and configured to press the outer electrode against the pipe. The leaf spring may include leaf spring pieces separated by slits, and the leaf spring pieces may each include a bent section bent along the edge and are configured to press the bar members in a position shifted from the bent sections toward the edge.

A laser processing method of performing laser processing on a transparent material that is transparent to ultraviolet light by using a laser processing system includes: performing relative positioning of a transfer position of a transfer image and the transparent material in an optical axis direction of a pulse laser beam so that the transfer position is set at a position inside the transparent material at a predetermined depth ΔZsf from a surface of the transparent material in the optical axis direction; and irradiating the transparent material with the pulse laser beam having a pulse width of 1 ns to 100 ns inclusive and a beam diameter of 10 μm to 150 μm inclusive at the transfer position.

A laser apparatus includes: (A) a solid-state laser apparatus that outputs burst seed pulsed light containing a plurality of pulses; (B) an excimer amplifier that amplifies the burst seed pulsed light in a discharge space in a single occurrence of discharge and outputs the amplified light as amplified burst pulsed light; (C) an energy sensor that measures the energy of the amplified burst pulsed light; and (D) a laser controller that corrects the timing at which the solid-state laser apparatus is caused to output the burst seed pulsed light based on the relationship of the difference between the timing at which the solid-state laser apparatus outputs the burst seed pulsed light and the timing at which the discharge occurs in the discharge space with a measured value of the energy.

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 laser apparatus includes a first optical element, a second optical element, a first actuator configured to change a first wavelength component included in a pulse laser beam by changing a posture of the first optical element, a second actuator configured to change a second wavelength component included in the pulse laser beam by changing a posture of the second optical element, a first encoder configured to measure a position of the first actuator, a second encoder configured to measure a position of the second actuator, and a processor. The processor reads a first relation and a second relation and performs control of the first actuator based on the first relation and the position of the first actuator measured by the first encoder and control of the second actuator based on the second relation and the position of the second actuator measured by the second encoder.

A laser device includes a first actuator configured to adjust an oscillation wavelength of pulse laser light; a second actuator configured to adjust a spectral line width of the pulse laser light; and a processor configured to determine a target spectral line width by reading data specifying a number of irradiation pulses of the pulse laser light with which one location of an irradiation receiving object is irradiated and a difference between a shortest wavelength and a longest wavelength, control the second actuator based on the target spectral line width, and control the first actuator so that the oscillation wavelength periodically changes every number of the irradiation pulses between the shortest wavelength and the longest wavelength.

A gas laser apparatus includes a chamber containing a laser gas, a pair of electrodes disposed within the chamber, a fan disposed within the chamber, a motor connected to a rotating shaft of the fan, and a rotating speed control unit configured to control a rotating speed of the fan based on a wear-out parameter of the pair of electrodes.

A laser crystallization method includes exciting gas medium in an airtight container to generate laser beams; amplifying the laser beams by reflecting the laser beams between a high reflection mirror and a low reflection mirror respectively disposed facing opposite end portions of the airtight container, wherein a first transparent window and a second transparent window are fixed to respective end portions of the airtight container, and outputting the amplified laser beams; and disposing a cleaning mirror in a path of the laser beams that have propagated through the second transparent window.

A laser crystallization method includes exciting gas medium in an airtight container to generate laser beams; amplifying the laser beams by reflecting the laser beams between a high reflection mirror and a low reflection mirror respectively disposed facing opposite end portions of the airtight container, wherein a first transparent window and a second transparent window are fixed to respective end portions of the airtight container, and outputting the amplified laser beams; and disposing a cleaning mirror in a path of the laser beams that have propagated through the second transparent window.