Singapore Synchrotron Light Source

Makes Light Work For You
  • EUV beamline

    Contact: Dr Yu Xiaojiang (slsyxjnus.edu.sg)
    Contact: Prof Mark B H Breese (slshead@nus.edu.sgnus.edu.sg)
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    Introduction
     
    • EUV branch beamline is relatively a new beamline at Singapore Synchrotron Light Source (SSLS) commissioned in March 2017
    • Beamline was funded by NRF with a budget of ~3M S$
    • HV Reflectometer designed for EUV mask (up to 6”x6”) characterization
    • Available spectral range is 70-110 eV
    • Beamline shares monochromator with another beamline at SSLS called SINS beamline
     
    Technical parameters
     
    Parameter Values/info
    Spectral resolution (E/ΔE) at 13.5 nm ~1.5.10-3 (50 um slits, 130 l/mm grat.)
    Spectral range 70-110 eV (11.3-17.7 nm)
    Spot size 3.1 mm x 1 mm (13.5 nm)
    Incident power at 13.5 nm
    Angular acceptance 0.5-1 mrad (vert.), 10 mrad (horiz.)
    Photon Flux ~2·109 photons/s·mm2 at 13.5 nm
    Filter wheel Si, Zr (300 nm each, self-standing)
    Detector Si photodiode (OptoDiode SXUV100)
    Sample stage 3 movements (X,Y,Z) 1 angle (θ)
    Detector stage 1 movement (Xd), 1 angle (θd)
    Available scans R vs λ, R vs θ, θ-2θ, Scatterometry, T vs λ, T vs θ (future)
    Average linear polarization 70-110 eV To be determined
    Average circular polarization 70-110 eV To be determined

     Other Beamline Parameters:
    • Covering 11-25 nm range (110-50 eV)
    • Holder for 6” x 6” optics
    • Measurements:
      I. Reflectometry: R or T vs λ

      R or T vs θ

      I. Scatterometry
    • Available filters: Si, Zr
    • Base pressure: 3x10-8 Torr
    • Excellent match with data obtained from Advanced Light Source, Berkeley, California
     Quality of measurements
    • ML Centroid Repeatability 5 pm
    • ML Reflectance Repeatability 0.1%
     
     Current and Future Applications
    • Characterization of EUV Multilayers
    • New Absorbers
    • Roughness/Scattering of Thin Films
    • New Buffer Layers
    • Actinic Defect Inspection
    • Many others!
     
    Beamline general scheme/location in SSLS
     
     
    Beamline architecture
     

  • Beamline Components

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    Horizontal and vertical focusing mirror chambers
     
     
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    Polarization definition slit chamber
     
     
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    Monochromator, entrance and exit slits
     
     
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    Horizontal and vertical focusing M1 and M2 mirror chambers
     
     
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    Filter chamber
     
     
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    Reflectometer (stages, detector, sample size)
     
     
     
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    Load Lock Chamber
     
     
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    Control Rack
     
     
  • Measurements with SSLS reflectometer

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    EUV beamline cross calibration
    Wavelength Final Calibration
    Si edge calibrated with Au O1 edge photo spectroscopy in SINS beamline
     
    Wavelength repeatability
    Plot displays the inflexion point wavelength of the S-like fitting curves
     
    Scan across Si L2 edge (x11)
    Scan Parameters:
    λ scan from 12.2-12.6 nm
    Step 0.005 nm, Si filter
    V. Slits 100 μm
    S-like curves fitted to data
    Wavelength Repeatability: 0.0006 nm
     
    Centroid repeatability
    Same plot measured 10 times without change in stages position
     
     
    Scan Centroid (nm)
    Advanced light source (ALS) (reference)13.394
    #1 13.3903
    #2 13.3908
    #3 13.3907
    #4 13.3903
    #5 13.3905
    #6 13.3907
    #7 13.3907
    #8 13.3906
    #9 13.3904
    #10 13.3906
    Sample DQE630007 same spot (x10)
     
    Scan Parameters:
    λ scan from 12.8-14 nm
    Step 0.02 nm, Si filter
    V. Slits 150 μm
     
    Centroid Repeatability: 0.0002 nm
     
    Reflectance @ centroid Repeatability
     
    Stages position changed after each scan; direct and reflected beam were measured
     
     
    ScanCentroid (nm)R @ centroid
    Advanced light source (ALS) (reference)13.3940.6094
    #113.3960.6038
    #213.39610.6034
    #313.39660.6057
     
    Change in stages:
    Direct Beam ConfigurationReflected Beam Configuration
    Detector θ0 degDetector θ168 deg
    Mask θ0 degMask θ84 deg
    Mask Z-12 mmMask Z0 mm
    Mask Y5 mmMask Y0 mm
    Mask X5 mmMask X0 mm
    Sample DQE630007 (x3)
    Scan Parameters:
    λ scan from 12.8-14 nm
    Step 0.02 nm, Si filter
    V. Slits 150 μm
    Centroid Repeatability: 0.0003 nm
    Reflectance @ centroid Repeatability: 0.0010
     
    Loading/unloading exercise
     
    Mask was unloaded from reflectometer and loaded 2 times
     
     
    Scan Centroid (nm)
    Advanced light source (ALS) (reference) 13.3940
    After 1st load 13.3906
    After 2nd load 13.3903
    (Reflectance scans) 13.3962
    Sample DQE630007, same spot (x3)
    Scan Parameters:
    λ scan from 12.8-14 nm
    Step 0.02 nm, Si filter
    V. Slits 150 μm
  • Publication

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    Rodriguez-De Marcos, L., Shenbaga, S. M. P., Bin Leong, O., Das, P. K., Breese, M. B. H., & Rusydi, A. (2020). Optical constants and absorption properties of Te and TeO thin films in the 13-14 nm spectral range. OPTICS EXPRESS, 28(9), 12922-12935. doi:10.1364/OE.381883