Abstract: A thermo-pump includes a sealed casing, divided into a main casing volume and one or more secondary volumes. A thermo-pump includes a shaft. A thermo-pump includes a displacer, coupled to the shaft and oscillates to create a pressure gain between a high-pressure phase and a low-pressure phase. A thermo-pump includes one or more displacer rings, wherein the displacer rings are made from a material with thermal properties below a threshold. A thermo-pump includes an insert, wherein the insert is configured to form a perimeter of the main casing volume, wherein the insert is made from a material with thermal properties below the threshold. A thermo-pump includes one or more bushings, wherein the one or more bushing separate the main casing volume and the one or more secondary volumes. A thermo-pump includes one or more gas bearings configured to prevent contact between the shaft and the sealed casing.

Abstract: A system for generating laser sustained broadband light includes a pump source configured to generate a pumping beam, a gas containment structure for containing a gas and a multi-pass optical assembly. The multi-pass optical assembly includes one or more optical elements configured to perform a plurality of passes of the pumping beam through a portion of the gas to sustain a broadband-light-emitting plasma. The one or more optical elements are arranged to collect an unabsorbed portion of the pumping beam transmitted through the plasma and direct the collected unabsorbed portion of the pumping beam back into the portion of the gas.

Abstract: A broadband radiation source is disclosed. The source may include a gas containment vessel configured to maintain a plasma and emit broadband radiation. The source may also include a recirculation gas loop fluidically coupled to the gas containment vessel. The recirculation gas loop may be configured to transport gas from one or more gas boosters configured to pressurize the low-pressure gas into a high-pressure gas and transport the high-pressure gas to the recirculation loop via an outlet. The system includes a pressurized gas reservoir fluidically coupled to the outlet of the one or more gas boosters and is configured to receive and store high pressure gas from the one or more gas boosters. The source includes a pressurized gas reservoir located between the one or more gas boosters and the gas containment vessel and is configured to receive and store high pressure gas from the one or more gas boosters.

Abstract: Methods and systems for enhanced defect detection based on images collected by at least two imaging detectors at different times are described. In some embodiments, the time between image measurements is at least 100 microseconds and no more than 10 milliseconds. In one aspect, one or more defects of interest are identified based on a composite image of a measured area generated based on a difference between collected images. In a further aspect, measurement conditions associated with the each imaged location are adjusted to be different for measurements performed by at least two imaging detectors at different times. In some embodiments, the measurement conditions are adjusted during the time between measurements by different imaging detectors. Exemplary changes of measurement conditions include environmental changes at the wafer under measurement and changes made to the optical configuration of the inspection system.

Abstract: A broadband radiation source is disclosed. The source may include a gas containment vessel configured to maintain a plasma and emit broadband radiation. The source may also include a recirculation gas loop fluidically coupled to the gas containment vessel. The recirculation gas loop may be configured to transport gas from one or more gas boosters configured to pressurize the low-pressure gas into a high-pressure gas and transport the high-pressure gas to the recirculation loop via an outlet. The system includes a pressurized gas reservoir fluidically coupled to the outlet of the one or more gas boosters and is configured to receive and store high pressure gas from the one or more gas boosters. The source includes a pressurized gas reservoir located between the one or more gas boosters and the gas containment vessel and is configured to receive and store high pressure gas from the one or more gas boosters.

Abstract: A plasma cell for use in a laser-sustained plasma light source includes a plasma bulb configured to contain a gas suitable for generating a plasma. The plasma bulb is transparent to light from a pump laser, wherein the plasma bulb is transparent to at least a portion of a collectable spectral region of illumination emitted by the plasma. The plasma bulb of the plasma cell is configured to filter short wavelength radiation, such as VUV radiation, emitted by the plasma sustained within the bulb in order to keep the short wavelength radiation from impinging on the interior surface of the bulb.

Abstract: A spectrometer apparatus is disclosed. The apparatus may include light source and the light source may include a chamber for sustaining a plasma within the internal volume of the chamber. The apparatus may also include a spectrometer cavity and a windowless entrance slit. The windowless entrance slit may fluidically and optically couple the spectrometer cavity and the internal volume of the chamber of the light source. Further, the apparatus may include a diffractive element disposed within the spectrometer cavity and a window positioned at an opposite end of the spectrometer cavity from the windowless slit. The apparatus may also include a camera and a spectrometer.

Abstract: A plasma cell for use in a laser-sustained plasma light source includes a plasma bulb configured to contain a gas suitable for generating a plasma. The plasma bulb is transparent to light from a pump laser, wherein the plasma bulb is transparent to at least a portion of a collectable spectral region of illumination emitted by the plasma. The plasma bulb of the plasma cell is configured to filter short wavelength radiation, such as VUV radiation, emitted by the plasma sustained within the bulb in order to keep the short wavelength radiation from impinging on the interior surface of the bulb.

Abstract: A system for generating laser sustained broadband light includes a pump source configured to generate a pumping beam, a gas containment structure for containing a gas and a multi-pass optical assembly. The multi-pass optical assembly includes one or more optical elements configured to perform a plurality of passes of the pumping beam through a portion of the gas to sustain a broadband-light-emitting plasma. The one or more optical elements are arranged to collect an unabsorbed portion of the pumping beam transmitted through the plasma and direct the collected unabsorbed portion of the pumping beam back into the portion of the gas.

Abstract: A system for generating laser sustained broadband light includes a pump source configured to generate a pumping beam, a gas containment structure for containing a gas and a multi-pass optical assembly. The multi-pass optical assembly includes one or more optical elements configured to perform a plurality of passes of the pumping beam through a portion of the gas to sustain a broadband-light-emitting plasma. The one or more optical elements are arranged to collect an unabsorbed portion of the pumping beam transmitted through the plasma and direct the collected unabsorbed portion of the pumping beam back into the portion of the gas.

Abstract: A system for pumping laser sustained plasma and enhancing one or more selected wavelengths of output illumination generated by the laser sustained plasma is disclosed. In embodiments, the system includes one or more pump modules configured to generate pump illumination for the laser sustained plasma and one or more enhancing illumination sources configured to generate enhancing illumination at one or more selected wavelengths. The pump illumination may be directed along one or more pump illumination paths that are non-collinear to an output illumination path of the output illumination. The enhancing illumination may be directed along an illumination path that is collinear to the output illumination path of the output illumination so that the enhancing illumination is combined with the output illumination, thereby enhancing the output illumination at the one or more selected wavelengths.

Abstract: Methods and systems for enhanced defect detection based on images collected by at least two imaging detectors at different times are described. In some embodiments, the time between image measurements is at least 100 microseconds and no more than 10 milliseconds. In one aspect, one or more defects of interest are identified based on a composite image of a measured area generated based on a difference between collected images. In a further aspect, measurement conditions associated with the each imaged location are adjusted to be different for measurements performed by at least two imaging detectors at different times. In some embodiments, the measurement conditions are adjusted during the time between measurements by different imaging detectors. Exemplary changes of measurement conditions include environmental changes at the wafer under measurement and changes made to the optical configuration of the inspection system.

Abstract: A system for generating pump illumination for laser sustained plasma (LSP) is disclosed. In embodiments, the system includes an illumination source configured to output illumination having a first spectral frequency and an optical frequency converter. The optical frequency converter can be configured to receive the illumination having the first spectral frequency from the illumination source and configured to output pump illumination having a second spectral frequency that is different from the first spectral frequency.

Abstract: A system for separating plasma pumping light and collected broadband light includes a pump source configured to generate pumping illumination including at least a first wavelength, a gas containment element for containing a volume of gas, a collector configured to focus the pumping illumination from the pumping source into the volume of gas to generate a plasma within the volume of gas, wherein the plasma emits broadband radiation including at least a second wavelength and an illumination separation prism element positioned between a reflective surface of the collector and the pump source and arranged to spatially separate the pumping illumination including the first wavelength and the emitted broadband radiation including at least a second wavelength emitted from the plasma.

Abstract: A system for generating pump illumination for laser sustained plasma (LSP) is disclosed. In embodiments, the system includes an illumination source configured to output illumination having a first spectral frequency and an optical frequency converter. The optical frequency converter can be configured to receive the illumination having the first spectral frequency from the illumination source and configured to output pump illumination having a second spectral frequency that is different from the first spectral frequency.

Abstract: A system for pumping laser sustained plasma and enhancing one or more selected wavelengths of output illumination generated by the laser sustained plasma is disclosed. In embodiments, the system includes one or more pump modules configured to generate pump illumination for the laser sustained plasma and one or more enhancing illumination sources configured to generate enhancing illumination at one or more selected wavelengths. The pump illumination may be directed along one or more pump illumination paths that are non-collinear to an output illumination path of the output illumination. The enhancing illumination may be directed along an illumination path that is collinear to the output illumination path of the output illumination so that the enhancing illumination is combined with the output illumination, thereby enhancing the output illumination at the one or more selected wavelengths.

Abstract: A spectrometer apparatus is disclosed. The apparatus may include light source and the light source may include a chamber for sustaining a plasma within the internal volume of the chamber. The apparatus may also include a spectrometer cavity and a windowless entrance slit. The windowless entrance slit may fluidically and optically couple the spectrometer cavity and the internal volume of the chamber of the light source. Further, the apparatus may include a diffractive element disposed within the spectrometer cavity and a window positioned at an opposite end of the spectrometer cavity from the windowless slit. The apparatus may also include a camera and a spectrometer.

Abstract: An optical system for generating broadband light via light-sustained plasma formation includes a chamber, an illumination source, a set of focusing optics, and a set of collection optics. The chamber is configured to contain a buffer material in a first phase and a plasma-forming material in a second phase. The illumination source generates continuous-wave pump illumination. The set of focusing optics focuses the continuous-wave pump illumination through the buffer material to an interface between the buffer material and the plasma-forming material in order to generate a plasma by excitation of at least the plasma-forming material. The set of collection optics receives broadband radiation emanated from the plasma.

Abstract: A laser-sustained plasma lamp includes a gas containment structure configured to contain a volume of gas. The gas containment structure is configured to receive pump illumination from a pump laser for generating a plasma within the volume of gas. The gas containment structure includes one or more transmissive structures being at least partially transparent to the pump illumination from the pump laser and at least a portion of the broadband radiation emitted by the plasma. The one or more transmissive structures have a graded absorption profile so as to control heating of the one or more transmissive structures caused by the broadband radiation emitted by the plasma.

Abstract: An optical system for generating broadband light via light-sustained plasma formation includes a chamber, an illumination source, a set of focusing optics, and a set of collection optics. The chamber is configured to contain a buffer material in a first phase and a plasma-forming material in a second phase. The illumination source generates continuous-wave pump illumination. The set of focusing optics focuses the continuous-wave pump illumination through the buffer material to an interface between the buffer material and the plasma-forming material in order to generate a plasma by excitation of at least the plasma-forming material. The set of collection optics receives broadband radiation emanated from the plasma.