Abstract: A system and method are provided for utilizing a focus state calibration object for determining calibration data for a variable focal length (VFL) lens system which includes a VFL lens (e.g., a tunable acoustic gradient lens). The calibration object includes a planar tilted pattern surface on which a set of focus state reference regions (FSRRs) are distributed (e.g., a tilted grating). The FSRRs have known geometric relationships relative to the planar tilted pattern surface and have known region relationships relative to one another. A plurality of camera images is acquired at different phase timings of the periodic modulation, and calibration data is determined based at least in part on analyzing the plurality of camera images. The determined calibration data indicates respective phase timings of the periodic modulation that correspond to respective effective focus positions of the VFL lens system.

Abstract: A method is provided for operating a tunable acoustic gradient (TAG) lens imaging system. The method includes: (a) providing a smart lighting pulse control routine/circuit (SLPCRC) that provides a first mode of exposure control corresponding to a points from focus (PFF) mode of the TAG lens imaging system and a second mode of exposure control corresponding to an extended depth of focus (EDOF) mode of the TAG lens imaging system; (b) placing a workpiece in a field of view of the TAG lens imaging system; and (c) periodically modulating a focus position of the TAG lens imaging system without macroscopically adjusting the spacing between elements in the TAG lens imaging system, wherein the focus position is periodically modulated over a plurality of focus positions along a focus axis direction in a focus range including a surface height of the workpiece, at a modulation frequency of at least 30 kHz.

Abstract: A moving property of a target is measured as the target travels toward a target space. The target including a component that emits light when converted to a plasma. A diagnostic probe system is interacted with a current target moving toward the target space. The interaction occurs prior to the current target entering the target space and after an immediately preceding target has interacted with a prior radiation pulse in the target space. First and second light that is produced at least in part from the interaction between the diagnostic probe system and the current target is detected prior to the current target entering the target space and after an immediately preceding target has interacted with the prior radiation pulse in the target space. One or more moving properties of the current target are determined based on an analysis of the detected first and second light.

Abstract: A system and method are provided for utilizing a focus state calibration object for determining calibration data for a variable focal length (VFL) lens system which includes a VFL lens (e.g., a tunable acoustic gradient lens). The calibration object includes a planar tilted pattern surface on which a set of focus state reference regions (FSRRs) are distributed (e.g., a tilted grating). The FSRRs have known geometric relationships relative to the planar tilted pattern surface and have known region relationships relative to one another. A plurality of camera images is acquired at different phase timings of the periodic modulation, and calibration data is determined based at least in part on analyzing the plurality of camera images. The determined calibration data indicates respective phase timings of the periodic modulation that correspond to respective effective focus positions of the VFL lens system.

Abstract: A moving property of a target is measured as the target travels toward a target space. The target including a component that emits light when converted to a plasma. A diagnostic probe system is interacted with a current target moving toward the target space. The interaction occurs prior to the current target entering the target space and after an immediately preceding target has interacted with a prior radiation pulse in the target space. First and second light that is produced at least in part from the interaction between the diagnostic probe system and the current target is detected prior to the current target entering the target space and after an immediately preceding target has interacted with the prior radiation pulse in the target space. One or more moving properties of the current target are determined based on an analysis of the detected first and second light.

Abstract: A method is provided for operating a tunable acoustic gradient (TAG) lens imaging system. The method includes: (a) providing a smart lighting pulse control routine/circuit (SLPCRC) that provides a first mode of exposure control corresponding to a points from focus (PFF) mode of the TAG lens imaging system and a second mode of exposure control corresponding to an extended depth of focus (EDOF) mode of the TAG lens imaging system; (b) placing a workpiece in a field of view of the TAG lens imaging system; and (c) periodically modulating a focus position of the TAG lens imaging system without macroscopically adjusting the spacing between elements in the TAG lens imaging system, wherein the focus position is periodically modulated over a plurality of focus positions along a focus axis direction in a focus range including a surface height of the workpiece, at a modulation frequency of at least 30 kHz.

Abstract: A moving property of a target is measured as the target travels toward a target space. The target including a component that emits light when converted to a plasma. A diagnostic probe system is interacted with a current target moving toward the target space. The interaction occurs prior to the current target entering the target space and after an immediately preceding target has interacted with a prior radiation pulse in the target space. First and second light that is produced at least in part from the interaction between the diagnostic probe system and the current target is detected prior to the current target entering the target space and after an immediately preceding target has interacted with the prior radiation pulse in the target space. One or more moving properties of the current target are determined based on an analysis of the detected first and second light.

Abstract: A moving property of a target is measured as the target travels toward a target space. The target including a component that emits light when converted to a plasma. A diagnostic probe system is interacted with a current target moving toward the target space. The interaction occurs prior to the current target entering the target space and after an immediately preceding target has interacted with a prior radiation pulse in the target space. First and second light that is produced at least in part from the interaction between the diagnostic probe system and the current target is detected prior to the current target entering the target space and after an immediately preceding target has interacted with the prior radiation pulse in the target space. One or more moving properties of the current target are determined based on an analysis of the detected first and second light.

Abstract: A method is described for measuring a moving property of a current target as it travels along a trajectory toward a target space. The method includes: detecting a plurality of two-dimensional representations of light that are produced due to an interaction between the current target and each of a plurality of diagnostic probes prior to the current target entering the target space; determining one or more moving properties of the current target based on an analysis of the detected plurality of two-dimensional representations of light, the determining being completed prior to the current target entering the target space; and, if the determined one or more moving properties of the current target are outside an acceptable range, adjusting one or more characteristics of a radiation pulse directed to the target space.

Abstract: A method is described for measuring a moving property of a current target as it travels along a trajectory toward a target space. The method includes: detecting a plurality of two-dimensional representations of light that are produced due to an interaction between the current target and each of a plurality of diagnostic probes prior to the current target entering the target space; determining one or more moving properties of the current target based on an analysis of the detected plurality of two-dimensional representations of light, the determining being completed prior to the current target entering the target space; and, if the determined one or more moving properties of the current target are outside an acceptable range, adjusting one or more characteristics of a radiation pulse directed to the target space.

Abstract: A method includes generating light in a light generating chamber, causing a portion of the generated light to pass through a tube having a roughened inner surface, and detecting the portion of the generated light that has passed through the tube using a photodetector. The roughened inner surface of the tube has a surface roughness sufficient to cause grazing incidences of light to be eliminated rather than to be reflected off the roughened inner surface. In one example, the method includes outputting a signal from the photodetector to a controller, with the signal corresponding to the detected portion of the generated light. The light generated in the light generating chamber can be extreme ultraviolet (EUV) light. In tests using roughened and non-roughened protection tubes, the roughened tube was found to minimize or essentially eliminate the contribution to EUV energy from grazing incidence reflections off the inner surface of the tube.

Abstract: A method is described for measuring a moving property of a current target as it travels along a trajectory toward a target space. The method includes: detecting a plurality of two-dimensional representations of light that are produced due to an interaction between the current target and each of a plurality of diagnostic probes prior to the current target entering the target space; determining one or more moving properties of the current target based on an analysis of the detected plurality of two-dimensional representations of light, the determining being completed prior to the current target entering the target space; and, if the determined one or more moving properties of the current target are outside an acceptable range, adjusting one or more characteristics of a radiation pulse directed to the target space.

Abstract: A method includes generating light in a light generating chamber, causing a portion of the generated light to pass through a tube having a roughened inner surface, and detecting the portion of the generated light that has passed through the tube using a photodetector. The roughened inner surface of the tube has a surface roughness sufficient to cause grazing incidences of light to be eliminated rather than to be reflected off the roughened inner surface. In one example, the method includes outputting a signal from the photodetector to a controller, with the signal corresponding to the detected portion of the generated light. The light generated in the light generating chamber can be extreme ultraviolet (EUV) light. In tests using roughened and non-roughened protection tubes, the roughened tube was found to minimize or essentially eliminate the contribution to EUV energy from grazing incidence reflections off the inner surface of the tube.

Abstract: 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.

Abstract: A protector for a viewport of a vacuum chamber includes a substrate material that absorbs radiation having a wavelength of an amplified light beam and radiation having a wavelength included in an emission spectra of a target material that produces EUV light when ionized by the amplified light beam. The substrate material transmits one or more of visible or near-infrared light. The protector also includes a layer formed on the substrate material, and the layer reflects radiation having the wavelength of the amplified light beam.

Abstract: 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.

Abstract: A method and apparatus for improved control of the trajectory and timing of droplets of target material in a laser produced plasma (LPP) extreme ultraviolet (EUV) light system is disclosed. A droplet illumination module generates two laser curtains for detecting the droplets. The first curtain is used for detecting the position of the droplets relative to a desired trajectory to the irradiation site so that the position of a droplet generator may be adjusted to direct the droplets to the irradiation site, as in the prior art. A droplet detection module detects each droplet as it passes through the second curtain, determines when the source laser should generate a pulse so that the pulse arrives at the irradiation site at the same time as the droplet, and sends a signal to the source laser to fire at the correct time.

Abstract: A method and apparatus for improved control of the trajectory and timing of droplets of target material in a laser produced plasma (LPP) extreme ultraviolet (EUV) light system is disclosed. A droplet illumination module generates two laser curtains for detecting the droplets. The first curtain is used for detecting the position of the droplets relative to a desired trajectory to the irradiation site so that the position of a droplet generator may be adjusted to direct the droplets to the irradiation site, as in the prior art. A droplet detection module detects each droplet as it passes through the second curtain, determines when the source laser should generate a pulse so that the pulse arrives at the irradiation site at the same time as the droplet, and sends a signal to the source laser to fire at the correct time.

Abstract: A method and apparatus for improved control of the trajectory and timing of droplets of target material in a laser produced plasma (LPP) extreme ultraviolet (EUV) light system is disclosed. A droplet illumination module generates a laser curtain, and sensors detect the droplets as they pass through the curtain. One sensor in combination with a controller detects the position of the droplets relative to a desired trajectory to the irradiation site so that a signal can be sent to an actuator of a droplet generator to adjust orientation of the droplet generator and direct subsequent droplets to the irradiation site, as in the prior art. A second sensor, or droplet detection module, also detects each droplet as it passes through the curtain, and in combination with a controller determines when the source laser should generate a pulse so that the pulse will arrive at the irradiation site at the same time as the droplet, and sends a signal to the source laser to fire at the correct time.

Abstract: A protector for a viewport of a vacuum chamber includes a substrate material that absorbs radiation having a wavelength of an amplified light beam and radiation having a wavelength included in an emission spectra of a target material that produces EUV light when ionized by the amplified light beam. The substrate material transmits one or more of visible or near-infrared light. The protector also includes a layer formed on the substrate material, and the layer reflects radiation having the wavelength of the amplified light beam.