[go: up one dir, main page]

WO2025073435A1 - Ensemble source de lumière à large bande - Google Patents

Ensemble source de lumière à large bande Download PDF

Info

Publication number
WO2025073435A1
WO2025073435A1 PCT/EP2024/075258 EP2024075258W WO2025073435A1 WO 2025073435 A1 WO2025073435 A1 WO 2025073435A1 EP 2024075258 W EP2024075258 W EP 2024075258W WO 2025073435 A1 WO2025073435 A1 WO 2025073435A1
Authority
WO
WIPO (PCT)
Prior art keywords
radiation
light source
source assembly
microstructures
broadband light
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
PCT/EP2024/075258
Other languages
English (en)
Inventor
Tanvi KARPATE
Amir Abdolvand
John Colin TRAVERS
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
ASML Netherlands BV
Original Assignee
ASML Netherlands BV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from EP23202487.7A external-priority patent/EP4538786A1/fr
Application filed by ASML Netherlands BV filed Critical ASML Netherlands BV
Publication of WO2025073435A1 publication Critical patent/WO2025073435A1/fr
Pending legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/35—Non-linear optics
    • G02F1/365—Non-linear optics in an optical waveguide structure
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/35—Non-linear optics
    • G02F1/3528—Non-linear optics for producing a supercontinuum

Definitions

  • the present invention relates to a broadband light source assembly.
  • a broadband light source assembly comprising a femtosecond pump laser and an all-normal dispersion optical fiber.
  • a lithographic apparatus is a machine constructed to apply a desired pattern onto a substrate.
  • a lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs).
  • a lithographic apparatus may, for example, project a pattern (also often referred to as “design layout” or “design”) at a patterning device (e.g., a mask) onto a layer of radiation-sensitive material (resist) provided on a substrate (e.g., a wafer).
  • Low-ki lithography may be used to process features with dimensions smaller than the classical resolution limit of a lithographic apparatus.
  • X is the wavelength of radiation employed
  • NA is the numerical aperture of the projection optics in the lithographic apparatus
  • CD is the “critical dimension” (generally the smallest feature size printed, but in this case half-pitch)
  • ki is an empirical resolution factor.
  • sophisticated fine-tuning steps may be applied to the lithographic projection apparatus and/or design layout.
  • RET resolution enhancement techniques
  • Examples of measurement systems that may be provided within a lithographic apparatus include: a topography measurement system (also known as a level sensor); a position measurement system (for example an interferometric device) for determining position of a reticle or wafer stage; and an alignment sensor for determining a position of an alignment mark. These measurement devices may use electromagnetic radiation to perform the measurement.
  • a topography measurement system also known as a level sensor
  • a position measurement system for example an interferometric device
  • an alignment sensor for determining a position of an alignment mark.
  • the radiation generated by broadband light source assembly i.e. output by the optical fiber
  • the broadband light source assembly may generate radiation having RIN ⁇ 10 -5 [Hz -1 / 2 ].
  • the optical fiber may comprise: a core region; and a cladding region surrounding the core region; wherein the core region and the cladding region comprise a material having a first refractive index, the cladding region additionally comprising a plurality of microstructures extending from an input end of the optical fiber along a longitudinal axis of the optical fiber to an output end of the optical fiber, the plurality of microstructures (i) arranged in a cross-sectional pattern comprising at least one ring of microstructures surrounding the core region, and (ii) having a second refractive index which is less than the first refractive index.
  • the plurality of microstructures may be hollow.
  • the plurality of microstructures may be airfilled.
  • the broadband light source assembly advantageously does not require that the optical fiber is enclosed in a reservoir (otherwise termed a housing, container or gas cell) comprising a gas.
  • a reservoir otherwise termed a housing, container or gas cell
  • the absence of any gas-related components reduces the size and complexity of the assembly.
  • the reduced size of the broadband light source assembly means that it is easily integratable into a suitable apparatus (e.g. a sensor).
  • a ratio between a diameter of each of the microstructures and a pitch of the microstructures may be in a range of 0.33-0.45, optionally in a range of 0.36-0.42.
  • the cross-sectional pattern may comprise a plurality of rings of microstructures surrounding the core region.
  • the cross-sectional pattern may comprise at least three rings of micro structures surrounding the core region, optionally at least four rings of micro structures surrounding the core region, optionally at least five rings of microstructures surrounding the core region.
  • a ring of microstructures immediately adjacent to the core region may have six micro structures.
  • Each of the at least one ring of microstructures may have a hexagonal shape.
  • the core region may have a diameter less than or equal to 3 pm.
  • the optical fiber may have a dispersion value, at a minimum dispersion wavelength, between - 1 ps/(nm*km) and -100 ps/(nm*km).
  • a method for generating broadband radiation comprising: providing pulses of radiation emitted from a femtosecond pump laser to an all-normal dispersion optical fiber, wherein the pulses of radiation have an energy per pump pulse of greater than 50 nJ, the optical fiber outputting the broadband radiation.
  • Figure 1 depicts a schematic overview of a lithographic apparatus
  • Figure 2 depicts a schematic overview of a lithographic cell
  • Figure 3 depicts a schematic representation of holistic lithography, representing a cooperation between three key technologies to optimize semiconductor manufacturing
  • Figure 4 depicts a schematic overview of a scatterometry metrology tool used as a metrology device
  • Figure 5 depicts a schematic overview of a level sensor metrology tool
  • Figure 6 depicts a schematic overview of an alignment sensor metrology tool
  • Figure 7 depicts a schematic overview of a broadband light source assembly
  • Figure 8 depicts a transverse cross section of an optical fiber used in the broadband light source assembly to illustrate dimensions of the optical fiber
  • Figures 9a-c illustrate how the diameter of a core region of the optical fiber may be measured;
  • Figure 10 depicts an example all-normal dispersion profile of the optical fiber;
  • Figure 11 depicts spectrally broadened plots of white light generated at different cross-section of fiber lengths highlighting the evolution mechanisms of white light generated by the optical fiber;
  • Figure 12 depicts a power spectral density plot of radiation generated by the broadband light source assembly.
  • the terms “radiation” and “beam” are used to encompass all types of electromagnetic radiation, including ultraviolet radiation (e.g. with a wavelength of 365, 248, 193, 157 or 126 nm) and EUV (extreme ultra-violet radiation, e.g. having a wavelength in the range of about 5-100 nm).
  • reticle may be broadly interpreted as referring to a generic patterning device that can be used to endow an incoming radiation beam with a patterned cross-section, corresponding to a pattern that is to be created in a target portion of the substrate.
  • the term “light valve” can also be used in this context.
  • examples of other such patterning devices include a programmable mirror array and a programmable LCD array.
  • FIG. 1 schematically depicts a lithographic apparatus LA.
  • the lithographic apparatus LA includes an illumination system (also referred to as illuminator) IL configured to condition a radiation beam B (e.g., UV radiation, DUV radiation or EUV radiation), a mask support (e.g., a mask table) MT constructed to support a patterning device (e.g., a mask) MA and connected to a first positioner PM configured to accurately position the patterning device MA in accordance with certain parameters, a substrate support (e.g., a wafer table) WT constructed to hold a substrate (e.g., a resist coated wafer) W and connected to a second positioner PW configured to accurately position the substrate support in accordance with certain parameters, and a projection system (e.g., a refractive projection lens system) PS configured to project a pattern imparted to the radiation beam B by patterning device MA onto a target portion C (e.g., comprising one or more dies) of the substrate W.
  • inspection tools may be included in the lithocell LC. If errors are detected, adjustments, for example, may be made to exposures of subsequent substrates or to other processing steps that are to be performed on the substrates W, especially if the inspection is done before other substrates W of the same batch or lot are still to be exposed or processed.
  • An inspection apparatus which may also be referred to as a metrology apparatus, is used to determine properties of the substrates W, and in particular, how properties of different substrates W vary or how properties associated with different layers of the same substrate W vary from layer to layer.
  • the inspection apparatus may alternatively be constructed to identify defects on the substrate W and may, for example, be part of the lithocell LC, or may be integrated into the lithographic apparatus LA, or may even be a stand-alone device.
  • the inspection apparatus may measure the properties on a latent image (image in a resist layer after the exposure), or on a semi-latent image (image in a resist layer after a post-exposure bake step PEB), or on a developed resist image (in which the exposed or unexposed parts of the resist have been removed), or even on an etched image (after a pattern transfer step such as etching).
  • the patterning process in a lithographic apparatus LA is one of the most critical steps in the processing which requires high accuracy of dimensioning and placement of structures on the substrate W.
  • three systems may be combined in a so called “holistic” control environment as schematically depicted in Fig. 3.
  • One of these systems is the lithographic apparatus LA which is (virtually) connected to a metrology tool MT (a second system) and to a computer system CL (a third system).
  • the key of such “holistic” environment is to optimize the cooperation between these three systems to enhance the overall process window and provide tight control loops to ensure that the patterning performed by the lithographic apparatus LA stays within a process window.
  • the process window defines a range of process parameters (e.g. dose, focus, overlay) within which a specific manufacturing process yields a defined result (e.g. a functional semiconductor device) - typically within which the process parameters in the lithographic process or patterning process are allowed to vary.
  • the computer system CL may use (part of) the design layout to be patterned to predict which resolution enhancement techniques to use and to perform computational lithography simulations and calculations to determine which mask layout and lithographic apparatus settings achieve the largest overall process window of the patterning process (depicted in Fig. 3 by the double arrow in the first scale SCI).
  • the resolution enhancement techniques are arranged to match the patterning possibilities of the lithographic apparatus LA.
  • the computer system CL may also be used to detect where within the process window the lithographic apparatus LA is currently operating (e.g. using input from the metrology tool MT) to predict whether defects may be present due to e.g. sub-optimal processing (depicted in Fig. 3 by the arrow pointing “0” in the second scale SC2).
  • the metrology tool MT may provide input to the computer system CL to enable accurate simulations and predictions, and may provide feedback to the lithographic apparatus LA to identify possible drifts, e.g. in a calibration status of the lithographic apparatus LA (depicted in Fig. 3 by the multiple arrows in the third scale SC3).
  • metrology tools MT In lithographic processes, it is desirable to make frequently measurements of the structures created, e.g., for process control and verification. Tools to make such measurement are typically called metrology tools MT. Different types of metrology tools MT for making such measurements are known, including scanning electron microscopes or various forms of scatterometer metrology tools MT. Scatterometers are versatile instruments which allow measurements of the parameters of a lithographic process by having a sensor in the pupil or a conjugate plane with the pupil of the objective of the scatterometer, measurements usually referred as pupil based measurements, or by having the sensor in the image plane or a plane conjugate with the image plane, in which case the measurements are usually referred as image or field based measurements.
  • Aforementioned scatterometers may measure gratings using light from soft x-ray and visible to near-IR wavelength range.
  • the scatterometer MT is an angular resolved scatterometer.
  • reconstruction methods may be applied to the measured signal to reconstruct or calculate properties of the grating.
  • Such reconstruction may, for example, result from simulating interaction of scattered radiation with a mathematical model of the target structure and comparing the simulation results with those of a measurement. Parameters of the mathematical model are adjusted until the simulated interaction produces a diffraction pattern similar to that observed from the real target.
  • the scatterometer MT is a spectroscopic scatterometer MT.
  • the radiation emitted by a radiation source is directed onto the target and the reflected or scattered radiation from the target is directed to a spectrometer detector, which measures a spectrum (i.e. a measurement of intensity as a function of wavelength) of the specular reflected radiation. From this data, the structure or profile of the target giving rise to the detected spectrum may be reconstructed, e.g. by Rigorous Coupled Wave Analysis and non-linear regression or by comparison with a library of simulated spectra.
  • the scatterometer MT is a ellipsometric scatterometer.
  • the ellipsometric scatterometer allows for determining parameters of a lithographic process by measuring scattered radiation for each polarization states.
  • Such metrology apparatus emits polarized light (such as linear, circular, or elliptic) by using, for example, appropriate polarization filters in the illumination section of the metrology apparatus.
  • a source suitable for the metrology apparatus may provide polarized radiation as well.
  • Various embodiments of existing ellipsometric scatterometers are described in US patent applications 11/451,599, 11/708,678, 12/256,780, 12/486,449, 12/920,968, 12/922,587, 13/000,229, 13/033,135, 13/533,110 and 13/891,410 incorporated herein by reference in their entirety.
  • the scatterometer MT is adapted to measure the overlay of two misaligned gratings or periodic structures by measuring asymmetry in the reflected spectrum and/or the detection configuration, the asymmetry being related to the extent of the overlay.
  • the two (typically overlapping) grating structures may be applied in two different layers (not necessarily consecutive layers), and may be formed substantially at the same position on the wafer.
  • the scatterometer may have a symmetrical detection configuration as described e.g. in co-owned patent application EP1,628,164A, such that any asymmetry is clearly distinguishable. This provides a straightforward way to measure misalignment in gratings.
  • Focus and dose may be determined simultaneously by scatterometry (or alternatively by scanning electron microscopy) as described in US patent application US2011-0249244, incorporated herein by reference in its entirety.
  • a single structure may be used which has a unique combination of critical dimension and sidewall angle measurements for each point in a focus energy matrix (FEM - also referred to as Focus Exposure Matrix). If these unique combinations of critical dimension and sidewall angle are available, the focus and dose values may be uniquely determined from these measurements.
  • FEM focus energy matrix
  • a metrology target may be an ensemble of composite gratings, formed by a lithographic process, mostly in resist, but also after etch process for example.
  • the pitch and line-width of the structures in the gratings strongly depend on the measurement optics (in particular the NA of the optics) to be able to capture diffraction orders coming from the metrology targets.
  • the diffracted signal may be used to determine shifts between two layers (also referred to ‘overlay’) or may be used to reconstruct at least part of the original grating as produced by the lithographic process. This reconstruction may be used to provide guidance of the quality of the lithographic process and may be used to control at least part of the lithographic process.
  • Targets may have smaller sub-segmentation which are configured to mimic dimensions of the functional part of the design layout in a target. Due to this sub-segmentation, the targets will behave more similar to the functional part of the design layout such that the overall process parameter measurements resembles the functional part of the design layout better.
  • the targets may be measured in an underfilled mode or in an overfdled mode. In the underfilled mode, the measurement beam generates a spot that is smaller than the overall target. In the overfdled mode, the measurement beam generates a spot that is larger than the overall target. In such overfilled mode, it may also be possible to measure different targets simultaneously, thus determining different processing parameters at the same time.
  • a metrology apparatus such as a scatterometer, is depicted in Figure 4. It comprises a broadband (white light) radiation projector 2 which projects radiation onto a substrate W. The reflected or scattered radiation is passed to a spectrometer detector 4, which measures a spectrum 6 (i.e. a measurement of intensity as a function of wavelength) of the specular reflected radiation. From this data, the structure or profile 8 giving rise to the detected spectrum may be reconstructed by processing unit PU, e.g. by Rigorous Coupled Wave Analysis and non-linear regression or by comparison with a library of simulated spectra as shown at the bottom of Figure 3.
  • processing unit PU e.g. by Rigorous Coupled Wave Analysis and non-linear regression or by comparison with a library of simulated spectra as shown at the bottom of Figure 3.
  • a scatterometer may be configured as a normal-incidence scatterometer or an oblique-incidence scatterometer.
  • a topography measurement system level sensor or height sensor.
  • Such a tool may be integrated in the lithographic apparatus, for measuring a topography of a top surface of a substrate (or wafer).
  • a map of the topography of the substrate also referred to as height map, may be generated from these measurements indicating a height of the substrate as a function of the position on the substrate.
  • This height map may subsequently be used to correct the position of the substrate during transfer of the pattern on the substrate, in order to provide an aerial image of the patterning device in a properly focus position on the substrate.
  • “height” in this context refers to a dimension broadly out of the plane to the substrate (also referred to as Z-axis).
  • the level or height sensor performs measurements at a fixed location (relative to its own optical system) and a relative movement between the substrate and the optical system of the level or height sensor results in height measurements at locations across the substrate.
  • the radiation source LSO may include a plurality of radiation sources having different colors, or wavelength ranges, such as a plurality of LEDs.
  • the radiation source LSO of the level sensor LS is not restricted to visible radiation, but may additionally or alternatively encompass UV and/or IR radiation and any range of wavelengths suitable to reflect from a surface of a substrate.
  • the projection grating PGR is a periodic grating comprising a periodic structure resulting in a beam of radiation BE1 having a periodically varying intensity.
  • the beam of radiation BE1 with the periodically varying intensity is directed towards a measurement location MLO on a substrate W having an angle of incidence ANG with respect to an axis perpendicular (Z-axis) to the incident substrate surface between 0 degrees and 90 degrees, typically between 70 degrees and 80 degrees.
  • the patterned beam of radiation BE1 is reflected by the substrate W (indicated by arrows BE2) and directed towards the detection unit LSD.
  • the level sensor further comprises a detection system comprising a detection grating DGR, a detector DET and a processing unit (not shown) for processing an output signal of the detector DET.
  • the detection grating DGR may be identical to the projection grating PGR.
  • the detector DET produces a detector output signal indicative of the light received, for example indicative of the intensity of the light received, such as a photodetector, or representative of a spatial distribution of the intensity received, such as a camera.
  • the detector DET may comprise any combination of one or more detector types.
  • the height level at the measurement location MLO can be determined.
  • the detected height level is typically related to the signal strength as measured by the detector DET, the signal strength having a periodicity that depends, amongst others, on the design of the projection grating PGR and the (oblique) angle of incidence ANG.
  • the projection unit LSP and/or the detection unit LSD may include further optical elements, such as lenses and/or mirrors, along the path of the patterned beam of radiation between the projection grating PGR and the detection grating DGR (not shown).
  • the detection grating DGR may be omitted, and the detector DET may be placed at the position where the detection grating DGR is located.
  • a level sensor LS may be configured to project an array of measurement beams BE1 onto the surface of the substrate W, thereby generating an array of measurement areas MLO or spots covering a larger measurement range.
  • a critical aspect of performance of the lithographic apparatus is therefore the ability to place the applied pattern correctly and accurately in relation to features laid down in previous layers (by the same apparatus or a different lithographic apparatus).
  • the substrate is provided with one or more sets of marks or targets.
  • Each mark is a structure whose position can be measured at a later time using a position sensor, typically an optical position sensor.
  • the position sensor may be referred to as “alignment sensor” and marks may be referred to as “alignment marks”.
  • a lithographic apparatus may include one or more (e.g. a plurality of) alignment sensors by which positions of alignment marks provided on a substrate can be measured accurately.
  • Alignment (or position) sensors may use optical phenomena such as diffraction and interference to obtain position information from alignment marks formed on the substrate.
  • An example of an alignment sensor used in current lithographic apparatus is based on a self-referencing interferometer as described in US6961116.
  • Various enhancements and modifications of the position sensor have been developed, for example as disclosed in US2015261097A1. The contents of all of these publications are incorporated herein by reference.
  • FIG. 6 is a schematic block diagram of an embodiment of a known alignment sensor AS, such as is described, for example, in US6961116, and which is incorporated by reference.
  • Radiation source RSO provides a beam RB of radiation of one or more wavelengths, which is diverted by diverting optics onto a mark, such as mark AM located on substrate W, as an illumination spot SP.
  • the diverting optics comprises a spot mirror SM and an objective lens OL.
  • the illumination spot SP, by which the mark AM is illuminated, may be slightly smaller in diameter than the width of the mark itself.
  • Radiation diffracted by the alignment mark AM is collimated (in this example via the objective lens OL) into an information-carrying beam IB.
  • the term “diffracted” is intended to include zero-order diffraction from the mark (which may be referred to as reflection).
  • a self-referencing interferometer SRI e.g. of the type disclosed in US6961116 mentioned above, interferes the beam IB with itself after which the beam is received by a photodetector PD. Additional optics (not shown) may be included to provide separate beams in case more than one wavelength is created by the radiation source RSO.
  • the photodetector may be a single element, or it may comprise a number of pixels, if desired.
  • the photodetector may comprise a sensor array.
  • the diverting optics which in this example comprises the spot mirror SM, may also serve to block zero order radiation reflected from the mark, so that the information-carrying beam IB comprises only higher order diffracted radiation from the mark AM (this is not essential to the measurement, but improves signal to noise ratios).
  • Intensity signals SI are supplied to a processing unit PU.
  • a processing unit PU By a combination of optical processing in the block SRI and computational processing in the unit PU, values for X- and Y-position on the substrate relative to a reference frame are output.
  • a single measurement of the type illustrated only fixes the position of the mark within a certain range corresponding to one pitch of the mark.
  • Coarser measurement techniques are used in conjunction with this to identify which period of a sine wave is the one containing the marked position.
  • the same process at coarser and/or finer levels may be repeated at different wavelengths for increased accuracy and/or for robust detection of the mark irrespective of the materials from which the mark is made, and materials on and/or below which the mark is provided.
  • the wavelengths may be multiplexed and demultiplexed optically so as to be processed simultaneously, and/or they may be multiplexed by time division or frequency division.
  • the alignment sensor and spot SP remain stationary, while it is the substrate W that moves.
  • the alignment sensor can thus be mounted rigidly and accurately to a reference frame, while effectively scanning the mark AM in a direction opposite to the direction of movement of substrate W.
  • the substrate W is controlled in this movement by its mounting on a substrate support and a substrate positioning system controlling the movement of the substrate support.
  • a substrate support position sensor e.g. an interferometer
  • one or more (alignment) marks are provided on the substrate support.
  • a measurement of the position of the marks provided on the substrate support allows the position of the substrate support as determined by the position sensor to be calibrated (e.g. relative to a frame to which the alignment system is connected).
  • a measurement of the position of the alignment marks provided on the substrate allows the position of the substrate relative to the substrate support to be determined.
  • FIG 7 illustrates a broadband light source assembly 100 according to embodiments of the present disclosure.
  • the broadband light source assembly 100 may be employed in any of the apparatuses described above.
  • the broadband light source assembly 100 comprises a femtosecond pump laser 20 and an all-normal dispersion optical fiber 10.
  • the femtosecond pump laser 20 is arranged to emit pulses of radiation.
  • the optical fiber 10 is coupled to the femtosecond pump laser 20 such that it is arranged to receive the pulses of radiation emitted by the femtosecond pump laser 20 at an input end of the optical fiber 10.
  • the femtosecond pump laser 20 may be configured to emit pulses of radiation having an energy per pump pulse of greater than 1 nJ.
  • the femtosecond pump laser 20 is configured to emit pulses of radiation having an energy per pump pulse of greater than 50 nJ.
  • femtosecond pump laser 20 may be configured to emit pulses of radiation having an energy per pump pulse of greater than 50 nJ, greater than 60 nJ, greater than 70 nJ, greater than 75 nJ, greater than 80 nJ, greater than 90 nJ, or greater than 100 nJ.
  • the femtosecond pump laser 20 may be configured to emit pulses of radiation having an energy per pump pulse of up to 500 nJ.
  • the pulses of radiation may have a peak power (i.e. the maximum optical power that that a pulse will attain) of at least 200kW, optionally at least 300kW, optionally at least 400k W, optionally at least 500kW, optionally at least 600k W, optionally at least 625kW.
  • a peak power i.e. the maximum optical power that that a pulse will attain
  • the pulses of radiation emitted by the femtosecond pump laser 20 may have a pulse duration of at least 10 fs.
  • the pulses of radiation emitted by the femtosecond pump laser 20 may have a pulse duration of less than 500 fs. That is, the pulses of radiation emitted by the femtosecond pump laser 20 may have a pulse duration in a range of 10-500 fs.
  • the pulses of radiation emitted by the femtosecond pump laser 20 may have a pulse duration of at least 100 fs.
  • the pulses of radiation emitted by the femtosecond pump laser 20 may have a pulse duration in a range of 125-175 fs, optionally in a range of 130-170 fs, optionally in a range of 140-160 fs.
  • the pulses of radiation emitted by the femtosecond pump laser 20 have a natural full-width half-maxima (FWHM).
  • the FWHM can for example be in a range from 2 nm-100 nm.
  • the pulses of radiation may have a central pump wavelength in the range of 700-1800 nm.
  • the central pump wavelength of the radiation pulses is 800 nm, in another example the central pump wavelength of the radiation pulses is 1027 nm, in yet another example the central pump wavelength of the radiation pulses is 1064 nm.
  • the pulses of radiation emitted by the femtosecond pump laser 20 may have a pulse repetition rate in a range from 1 MHz - 10 GHz.
  • the pulses of radiation emitted by the femtosecond pump laser 20 may have a pulse repetition rate in a range from 1 - 100 MHz, optionally in a range of 10 - 90 MHz, optionally in a range of 20 - 80 MHz, optionally in a range of 30 - 70 MHz.
  • the pulse repetition rate may be 40 MHz.
  • the optical fiber 10 is an all-normal dispersion optical fiber. That is, the all-normal dispersion optical fiber 10 has a flattened convex profile of normal group velocity dispersion (GVD) with a distinct point where the dispersion is closest to zero at a minimum dispersion wavelength (MDW), but exhibits no zero dispersion wavelength (ZDW) in the region of interest.
  • VMD normal group velocity dispersion
  • ZDW zero dispersion wavelength
  • the central pump wavelength of the radiation pulses is within +/- 50 nm around the MDW to maximize the spectral broadening of the radiation input into the optical fiber 10.
  • the optical fiber 10 may include a core region and a cladding region surrounding the core region. Both the core region and the cladding region comprise a background material 12 having a first refractive index (n B ).
  • the cladding region additionally comprises a plurality of microstructures 14 (otherwise termed inclusions) extending from an input end of the optical fiber 10 along a longitudinal axis (in the z-direction) of the fiber to an output end of the optical fiber 10.
  • the plurality of microstructures have a second refractive index (n mc ) where n mc ⁇ n B .
  • the plurality of microstructures 14 are hollow. In some embodiments, the hollow microstructures 14 comprise air. In other embodiments, the plurality of microstructures 14 comprise a vacuum. In yet further embodiments, the plurality of microstructures 14 comprise a medium having the second refractive index (n mc ). This medium may be a solid material such as doped silica.
  • the doping material may for example be Fluorine (F), Germanium (Ge), and/or phosphorus (P).
  • the doped silica comprises silica doped with fluorine
  • the mole percentage of the fluorine may for example be in a range of 1-10%, such as in a range of 3-8%.
  • the plurality of microstructures 14 in the cladding region are arranged in a cross-sectional pattern comprising at least one ring of microstructures surrounding the core region.
  • the phrase “ring of microstructures” refers to the cladding microstructures typically having substantially equal radial distance to the core and being aligned in a ring configuration surrounding the core.
  • a ring of microstructures may not be fully circular.
  • a ring of microstructures may be arranged in a hexagonal shape (or other shape with a number of soft angles). It will be appreciated that this is merely an example and a ring of microstructures may be arranged in a circular or elliptical shape.
  • all the microstructures 14 of a ring of microstructures are of substantially the same size and shape (as shown in Figure 8) however it will be appreciated that one or more of the microstructures 14 may be sized differently and/or have a different cross-sectional shape than the remaining microstructures.
  • Figure 8 shows the optical fiber 10 having five rings of microstructures 14 it will be appreciated that this is merely an example. In some embodiments, there is only a single ring of microstructures. In other embodiments, there are multiple rings of microstructures for example at least two rings, such as at least three rings, such as at least four rings, such as at least five rings of microstructures 14.
  • each microstructure has a diameter (d), and a pitch A of the microstructures is defined as the center-to-center distance between neighboring microstructures.
  • a contributing factor to the optical properties of the optical fiber 10 is the normalized inclusion diameter (d/A) which corresponds to a ratio of the diameter (d) of each of the microstructures and the pitch A of the microstructures.
  • the normalized inclusion diameter (d/A) may be in a range of 0.33- 0.45, optionally in a range of 0.36-0.42.
  • the normalized inclusion diameter (d/A) may be 0.39.
  • the ring of microstructures which is closest to (i.e. immediately adjacent to) the core region may have six micro structures. The diameter of the core region is shown in Figure 8
  • the ring of microstructures which is closest to (i.e. immediately adjacent to) the core region having six microstructures is merely an example and embodiments of the present disclosure extend to optical fibers which have a different number of microstructures in the ring of microstructures which is closest to (i.e. immediately adjacent to) the core region.
  • the ring of microstructures which is closest to (i.e. immediately adjacent to) the core region has twelve microstructures.
  • the core region has a maximum extent (as illustrated in Figure 9a), and a minimum extent (as illustrated in Figure 9b), and the diameter of the core region D core is defined as the average of the maximum extent of the core region, and the minimum extent of the core region.
  • Figure 9a illustrates how the measurement of the diameter of the maximum extent of the core region is performed.
  • the diameter of the maximum extent of the core region corresponds to a distance between microstructures at opposing vertices of the hexagonal ring of microstructures which is closest to (i.e. immediately adjacent to) the core region.
  • Microstructures at vertices of the hexagonal ring of microstructures which may be used in the calculation of D C ore-max are shown in Figure 9a by way of a crosshatch pattern.
  • the diameter of the maximum extent of the core region D C o re -m a xis given by:
  • Figure 9b illustrates how the measurement of the diameter of the minimum extent of the core region D C ore-mm is performed.
  • the diameter of the minimum extent of the core region (D C ore-mm) corresponds to a distance between microstructures at opposing sides of the hexagonal ring of microstructures which is closest to (i.e. immediately adjacent to) the core region.
  • Microstructures at sides of the hexagonal ring of microstructures which may be used in the calculation of D C ore-min are shown in Figure 9b by way of a crosshatch pattern.
  • the diameter of the minimum extent of the core region D C ore-minis given by:
  • Figure 9c illustrates how the measurement of the diameter of the core region D cor e is performed when the core region has a maximum extent and a minimum extent.
  • microstructures at both vertices and sides of the hexagonal ring of microstructures which are used in the calculation of D cor e are shown in Figure 9c by way of a crosshatch pattern.
  • the diameter of the core region D cor e is given by:
  • the diameter of the core region D cor e may be less than or equal to 3 pm.
  • the diameter of the core region D cor e may be in a range of 2-3 pm, optionally in a range of 2.1-2.6 pm.
  • the optical fiber 10 may be either a polarization -maintaining (PM) fiber or a non-PM fiber.
  • a PM fiber is a fiber in which linear polarization can be maintained if linearly polarized light is launched into the fiber.
  • the launched polarized light maintains a linear polarization during propagation along the PM delivery fiber and exits the fiber in a linear polarization state.
  • a PM PCF 10 may be achieved by incorporating stress elements (e.g. stress rods) into the fiber.
  • the stress elements are included in the cladding region and are enclosed by the background material 12 in the cladding region.
  • the stress elements extend from an input end of the fiber along a longitudinal axis (in the z-direction) of the fiber to an output end of the fiber.
  • the stress elements induce a stress in the core region (providing birefringence).
  • the stress elements may have any appropriate cross-sectional shape such as circular, triangular, quadratic, polygonal e.g. hexagonal, elliptical, etc.
  • Figure 10 illustrates an all-normal dispersion profile of an example optical fiber 10.
  • the allnormal dispersion profile illustrated in Figure 10 is of an optical fiber 10 designed for a MDW at 1027 nm, with a core diameter D cor e of 2.3 pm, having 5 air-hole rings, whereby the air-holes have a pitch of 1.44 pm, normalized inclusion diameter (d/A) of 0.39, with the air-holes each having a diameter of 0.5616 pm.
  • the specific parameter specified above for the optical fiber 10 are merely examples.
  • the optical fiber 10 has a MDW at 1027 nm at which it exhibits a dispersion of -17 ps/(nm*km).
  • the optical fiber 10 may have a dispersion value at a MDW between -1 ps/(nm*km) and -100 ps/(nm*km), optionally between -1 ps/(nm*km) and -50 ps/(nm*km).
  • the broadband light source assembly 100 may be configured to generate broadband radiation (output by the optical fiber 10) in a wavelength range of at least 500-900 nm.
  • the lower bound for this broadband radiation wavelength range may be at least 100 nm, at least 200 nm, at least 300 nm, or at least 400 nm.
  • the upper bound for this broadband radiation wavelength range may be 2000 nm or less, 1800 nm or less, 1500 nm or less, or 1200 nm or less.
  • the broadband light source assembly 100 is configured to generate broadband radiation in a wavelength range of 485-1800 nm.
  • Broadband radiation may be radiation that spans across a wavelength range significantly larger than narrowband or single wavelength radiation.
  • Broadband radiation comprises a continuous, or substantially continuous range of wavelengths.
  • a range of wavelengths may also referred to as a spectrum/spectral range.
  • the continuous range of wavelengths may be over a range of at least 10 nm, 20 nm, 50nm, 100 nm, 200nm, 400nm or more.
  • the broadband radiation may have gaps in the wavelength range.
  • gaps may separate one or more continuous sub ranges within the wavelength range.
  • a substantially continuous range may have discrete wavelength(s) and/or narrow wavelength band(s) missing from the range, and still be considered continuous.
  • the power spectral density may be non-continuous, the power may vary across the broadband wavelength range.
  • the broadband radiation may comprise supercontinuum radiation.
  • the supercontinuum radiation may comprise for example electromagnetic radiation over a wavelength range of 500-900 nm.
  • the lower bound for this supercontinuum radiation wavelength range may be at least 100 nm, at least 200 nm, at least 300 nm, or at least 400 nm.
  • the upper bound for this supercontinuum radiation wavelength range may be 2000 nm or less, 1800 nm or less, 1500 nm or less, or 1200 nm or less.
  • the broadband light source assembly 100 is configured to generate supercontinuum radiation in a wavelength range of 485-1800 nm.
  • the supercontinuum radiation may comprise white light.
  • a “supercontinuum” refers generally to a continuous spectral power distribution that exhibits substantial flatness.
  • the supercontinuum comprises a continuous spectral power distribution over a wavelength range of at least 100 nm.
  • the flatness of the supercontinuum corresponds to a peak to trough spectral power ratio of less than 100:1, or 20 dB.
  • the flatness of the supercontinuum corresponds to a peak to trough spectral power ratio of less than 10:1, or 10 dB.
  • the inherent mechanism that leads to white light generation in the broadband light source assembly 100 is self-phase modulation leading to optical wave-breaking.
  • Figure 11 shows spectrally broadened plots of white light generated at different cross-sections of fiber lengths showing the evolution of white light spectra leading to the broadest white light generation. In Figure 11, these mechanisms can be identified by characteristic self-phase modulation fringes around the pump wavelength (which in this example was 1027 nm), followed by smooth optical wavebreaking (for the widest spectra shown).
  • the waveform 1102 is a plot of radiation generated at a distance of 0.5cm from the input end of the optical fiber 10 into which the pulses of radiation emitted by the femtosecond pump laser 20 are supplied.
  • the waveform 1104 is a plot of radiation generated at a distance of 1.5cm from the input end of the optical fiber 10.
  • the waveform 1106 is a plot of radiation generated at a distance of 3.75cm from the input end of the optical fiber 10.
  • the waveform 1108 is a plot of radiation generated at a distance of 12.75cm from the input end of the optical fiber 10. As shown in Figure 11, the spectrum of radiation generated along the fiber gets broader as the distance from the input end of the optical fiber 10 increases.
  • the broadband radiation output by the optical fiber 10 may have a power spectral density of at least 3 mW/nm in a wavelength band of 500-900 nm.
  • Figure 12 depicts a power spectral density plot of radiation that may be generated by a broadband light source assembly according to embodiments of the present invention.
  • the power spectral density plot on Figure 12 was obtained using a femtosecond pump laser 20 configured to emit pulses of radiation having a pulse duration of 150 fs centered at 1027 nm with 100 nJ of pump energy.
  • the power spectral density plot on Figure 12 was obtained using an optical fiber 10 designed for MDW at 1027 nm, with a core diameter D core of 2.3 pm, having 5 air-hole rings, whereby the air-holes have a pitch of 1.44 pm, normalized inclusion diameter (d/A) of 0.39, with the air-holes each having a diameter of 0.5616 pm.
  • D/A normalized inclusion diameter
  • the specific parameter specified above for both the femtosecond pump laser 20 and the optical fiber 10 are merely examples. It may be observed that the spectrum may drop below 3 mW/nm in a long wavelength range (e.g. 800-900 nm), this is illustrated in Figure 12. However, this can be easily increased to cross 3mW/nm for the long wavelength range by slight varying the input energy of the pulses of radiation emitted by the femtosecond pump laser 20.
  • the radiation generated by the optical fiber 10 has lower levels of relative intensity noise (RIN) than known light source assemblies which are based on solitonic and modulation instability (MI) seeded processes.
  • RIN relative intensity noise
  • MI modulation instability
  • RIN and dose noise are different.
  • RIN is pulse-to-pulse fluctuations in power and is caused by the physics of whitelight generation. It is independent of the repetition rate of the laser.
  • a broadband light source assembly comprising: a femtosecond pump laser arranged to emit pulses of radiation, wherein the pulses of radiation have an energy per pump pulse of greater than 50 nJ; and an all-normal dispersion optical fiber arranged to receive the pulses of radiation.
  • the optical fiber comprises: a core region; and a cladding region surrounding the core region; wherein the core region and the cladding region comprise a material having a first refractive index, the cladding region additionally comprising a plurality of microstructures extending from an input end of the optical fiber along a longitudinal axis of the optical fiber to an output end of the optical fiber, the plurality of microstructures (i) arranged in a cross- sectional pattern comprising at least one ring of microstructures surrounding the core region, and (ii) having a second refractive index which is less than the first refractive index.
  • a broadband light source assembly of clause 6, wherein the cross-sectional pattern comprises at least three rings of microstructures surrounding the core region, optionally at least four rings of microstructures surrounding the core region, optionally at least five rings of microstructures surrounding the core region.
  • a lithographic apparatus comprising the broadband light source assembly of any preceding clause.
  • a metrology apparatus comprising the broadband light source assembly of any of clauses 1 to 19.
  • a method for generating broadband radiation comprising providing pulses of radiation emitted from a femtosecond pump laser to an all-normal dispersion optical fiber, wherein the pulses of radiation have an energy per pump pulse of greater than 50 nJ, the optical fiber outputting the broadband radiation.
  • a broadband light source assembly in accordance with any of the embodiments described herein may be used in a lithographic apparatus LA such as that depicted in Figure 1.
  • a lithographic apparatus LA such as that depicted in Figure 1.
  • Possible other applications include the manufacture of integrated optical systems, guidance and detection patterns for magnetic domain memories, flat-panel displays, liquid-crystal displays (LCDs), thin-film magnetic heads, etc.
  • the broadband light source assembly may form part of a mask inspection apparatus, a metrology apparatus, or any apparatus that measures or processes an object such as a wafer (or other substrate) or mask (or other patterning device).
  • lithographic tools may use vacuum conditions or ambient (non-vacuum) conditions. That is, a broadband light source assembly in accordance with any of the embodiments described herein may be used in a metrology apparatus such as that depicted in Figure 4.
  • a broadband light source assembly in accordance with any of the embodiments described herein may be used in a level sensor LS such as that depicted in Figure 5.
  • a broadband light source assembly in accordance with any of the embodiments described herein may be used in an alignment sensor such as that depicted in Figure 6.

Landscapes

  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Exposure And Positioning Against Photoresist Photosensitive Materials (AREA)

Abstract

L'invention concerne un ensemble source de lumière à large bande, un appareil de métrologie et un procédé de génération de rayonnement à large bande. La source de lumière à large bande comprend un laser à pompe femtoseconde conçu pour émettre des impulsions de rayonnement, les impulsions de rayonnement ayant une énergie par impulsion de pompe supérieure à 50 nJ; et comprend une fibre optique de dispersion entièrement normale agencée pour recevoir les impulsions de rayonnement.
PCT/EP2024/075258 2023-10-02 2024-09-10 Ensemble source de lumière à large bande Pending WO2025073435A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
EP23201262.5 2023-10-02
EP23201262 2023-10-02
EP23202487.7 2023-10-09
EP23202487.7A EP4538786A1 (fr) 2023-10-09 2023-10-09 Ensemble source de lumière à large bande

Publications (1)

Publication Number Publication Date
WO2025073435A1 true WO2025073435A1 (fr) 2025-04-10

Family

ID=92712575

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2024/075258 Pending WO2025073435A1 (fr) 2023-10-02 2024-09-10 Ensemble source de lumière à large bande

Country Status (1)

Country Link
WO (1) WO2025073435A1 (fr)

Citations (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6952253B2 (en) 2002-11-12 2005-10-04 Asml Netherlands B.V. Lithographic apparatus and device manufacturing method
US6961116B2 (en) 2002-06-11 2005-11-01 Asml Netherlands B.V. Lithographic apparatus, device manufacturing method, and device manufactured thereby
EP1628164A2 (fr) 2004-08-16 2006-02-22 ASML Netherlands B.V. Procédé et dispositif pour caractérisation de la lithographie par spectrométrie à résolution angulaire
US7265364B2 (en) 2004-06-10 2007-09-04 Asml Netherlands B.V. Level sensor for lithographic apparatus
US7646471B2 (en) 2003-01-14 2010-01-12 Asml Netherlands B.V. Lithographic apparatus, level sensor, method of inspection, device manufacturing method, and device manufactured thereby
US20100233600A1 (en) 2009-03-13 2010-09-16 Asml Netherlands B.V. Level sensor arrangement for lithographic apparatus and device manufacturing method
US20100328655A1 (en) 2007-12-17 2010-12-30 Asml, Netherlands B.V. Diffraction Based Overlay Metrology Tool and Method
WO2011012624A1 (fr) 2009-07-31 2011-02-03 Asml Netherlands B.V. Procédé et appareil de métrologie, système lithographique et cellule de traitement lithographique
US20110026032A1 (en) 2008-04-09 2011-02-03 Asml Netherland B.V. Method of Assessing a Model of a Substrate, an Inspection Apparatus and a Lithographic Apparatus
US20110102753A1 (en) 2008-04-21 2011-05-05 Asml Netherlands B.V. Apparatus and Method of Measuring a Property of a Substrate
US20110249244A1 (en) 2008-10-06 2011-10-13 Asml Netherlands B.V. Lithographic Focus and Dose Measurement Using A 2-D Target
US20120044470A1 (en) 2010-08-18 2012-02-23 Asml Netherlands B.V. Substrate for Use in Metrology, Metrology Method and Device Manufacturing Method
US20150261097A1 (en) 2012-07-30 2015-09-17 Asml Netherlands B.V. Position Measuring Apparatus, Position Measuring Method, Lithographic Apparatus and Device Manufacturing Method
US20160161863A1 (en) 2014-11-26 2016-06-09 Asml Netherlands B.V. Metrology method, computer product and system
WO2016102127A1 (fr) 2014-12-22 2016-06-30 Asml Netherlands B.V. Capteur de niveau, appareil lithographique, et procédé de fabrication d'un dispositif
US20160370717A1 (en) 2015-06-17 2016-12-22 Asml Netherlands B.V. Recipe selection based on inter-recipe consistency

Patent Citations (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6961116B2 (en) 2002-06-11 2005-11-01 Asml Netherlands B.V. Lithographic apparatus, device manufacturing method, and device manufactured thereby
US6952253B2 (en) 2002-11-12 2005-10-04 Asml Netherlands B.V. Lithographic apparatus and device manufacturing method
US7646471B2 (en) 2003-01-14 2010-01-12 Asml Netherlands B.V. Lithographic apparatus, level sensor, method of inspection, device manufacturing method, and device manufactured thereby
US7265364B2 (en) 2004-06-10 2007-09-04 Asml Netherlands B.V. Level sensor for lithographic apparatus
EP1628164A2 (fr) 2004-08-16 2006-02-22 ASML Netherlands B.V. Procédé et dispositif pour caractérisation de la lithographie par spectrométrie à résolution angulaire
US20100328655A1 (en) 2007-12-17 2010-12-30 Asml, Netherlands B.V. Diffraction Based Overlay Metrology Tool and Method
US20110026032A1 (en) 2008-04-09 2011-02-03 Asml Netherland B.V. Method of Assessing a Model of a Substrate, an Inspection Apparatus and a Lithographic Apparatus
US20110102753A1 (en) 2008-04-21 2011-05-05 Asml Netherlands B.V. Apparatus and Method of Measuring a Property of a Substrate
US20110249244A1 (en) 2008-10-06 2011-10-13 Asml Netherlands B.V. Lithographic Focus and Dose Measurement Using A 2-D Target
US20100233600A1 (en) 2009-03-13 2010-09-16 Asml Netherlands B.V. Level sensor arrangement for lithographic apparatus and device manufacturing method
WO2011012624A1 (fr) 2009-07-31 2011-02-03 Asml Netherlands B.V. Procédé et appareil de métrologie, système lithographique et cellule de traitement lithographique
US20120044470A1 (en) 2010-08-18 2012-02-23 Asml Netherlands B.V. Substrate for Use in Metrology, Metrology Method and Device Manufacturing Method
US20150261097A1 (en) 2012-07-30 2015-09-17 Asml Netherlands B.V. Position Measuring Apparatus, Position Measuring Method, Lithographic Apparatus and Device Manufacturing Method
US20160161863A1 (en) 2014-11-26 2016-06-09 Asml Netherlands B.V. Metrology method, computer product and system
WO2016102127A1 (fr) 2014-12-22 2016-06-30 Asml Netherlands B.V. Capteur de niveau, appareil lithographique, et procédé de fabrication d'un dispositif
US20160370717A1 (en) 2015-06-17 2016-12-22 Asml Netherlands B.V. Recipe selection based on inter-recipe consistency

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
KNIGHT J C ET AL: "Hollow-core photonic crystal fibres for delivery and compression of ultrashort optical pulses", OPTICAL AND QUANTUM ELECTRONICS, KLUWER ACADEMIC PUBLISHERS, BO, vol. 39, no. 12-13, 13 November 2007 (2007-11-13), pages 1047 - 1056, XP019612803, ISSN: 1572-817X *
L E HOOPER ET AL: "Coherent supercontinuum generation in photonic crystal fiber with all-normal group velocity dispersion References and links 6 / OPTICS EXPRESS 4902", NATURE OPT. LETT. APPL. PHYS. B OPT. LETT. OPT. LETT. OPT. EXPRESS NATURE OPT. LETT. REV. MOD. PHYS. J. OPT. SOC. AM. B PHYS. REV. LETT. J. OPT. SOC. AM. B OPT. EXPRESS OSA MARCH OPT. EXPRESS J. OPT. SOC. AM. B OPT. EXPRESS J. OPT. SOC. AM. B OPT. LE, 1 March 2011 (2011-03-01), pages 847 - 851, XP055632639, Retrieved from the Internet <URL:https://www.osapublishing.org/DirectPDFAccess/42B7CFEB-03FB-6233-0F3137FF2F2F942C_210527/oe-19-6-4902.pdf?da=1&id=210527&seq=0&mobile=no> *
SUKHOIVANOV IGOR A ET AL: "Design of All-Normal Dispersion Microstructured Optical Fiber on Silica Platform for Generation of Pulse-Preserving Supercontinuum Under Excitation at 1550 nm", JOURNAL OF LIGHTWAVE TECHNOLOGY, IEEE, USA, vol. 35, no. 17, 1 September 2017 (2017-09-01), pages 3772 - 3779, XP011657396, ISSN: 0733-8724, [retrieved on 20170720], DOI: 10.1109/JLT.2017.2652379 *

Similar Documents

Publication Publication Date Title
US11754906B2 (en) Hollow-core photonic crystal fiber based optical component for broadband radiation generation
JP7670904B2 (ja) 放射源
US11372154B2 (en) Method, assembly, and apparatus for improved control of broadband radiation generation
US11275313B2 (en) Metrology apparatus with radiation source having multiple broadband outputs
US12130538B2 (en) Broadband radiation generation in hollow-core fibers
EP3805857A1 (fr) Génération améliorée de rayonnements à bande large dans des fibres à noyau creux
EP3715944A1 (fr) Appareil et procédé d&#39;élargissement de fréquence
EP4623339A1 (fr) Circuit intégré photonique pour générer un rayonnement à large bande
EP4538786A1 (fr) Ensemble source de lumière à large bande
EP3796080A1 (fr) Source de radiation
WO2025073435A1 (fr) Ensemble source de lumière à large bande
EP4451021A1 (fr) Fibre à cristal photonique
TW202534413A (zh) 寬頻帶光源總成
EP3865931A1 (fr) Procédé, ensemble et appareil de commande améliorée de génération de rayonnements à large bande
IL322006A (en) System and method for producing supercontinuum radiation
NL2024880A (en) Method, assembly, and apparatus for improved control of broadband radiation generation

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 24768562

Country of ref document: EP

Kind code of ref document: A1