NIST EUVL Metrology Programs S.Grantham, C. Tarrio, R.E. Vest, Y. Barad, S. Kulin, K. Liu and T.B. Lucatorto National Institute of Standards and Technology (NIST) Gaithersburg, MD USA L. Klebanoff and M. Malinowski Sandia National Laboratory Livermore, CA USA S. Bajt Lawrence Livermore National Laboratory Livermore, CA USA
Outline SURF III EUV Reflectometry Detector Calibrations EUV Optic Endurance Testing Summary
SURF III
4 5 6 7 8 3 2 10 11 9 1 Beamlines at SURF III 1. EUV Multilayer Endurance testing 2. NASA Calibrations: Source Based Radiometry 3. Source Based Radiometry -Beam Current Measurements (Electron Counting) -Source Calibrations 4. Detector Based Radiometry Normal Incidence (ACR): UV DUV 5. DUV Fourier Transform Spectrometer: Optical Constants at 156nm 6. Beam Diagnostics Beam Imaging (Beam Size and Stability) 7. NIST/DARPA Reflectometer 8. Open 9. Detector Based Radiometry Grazing Incidence (Ion Chamber): EUV 10.Beam Diagnostics Noise Measurements / Bunch Length 11.Beam Diagnostics Current Monitor (Electron Counting)
SURF III Output Spectrum 10 MeV < E 0 < 380 MeV Flux (Photons / s) at θ = 4, 100 ma, 1% b.w. 6*10 14 5*10 14 4*10 14 3*10 14 2*10 14 10 14 0 EUV DUV Visible 380 MeV, λ c = 8.5 nm 331 MeV, λ c = 13 nm 284 MeV, λ c = 20 nm 234 MeV, λ c = 36 nm 183 MeV, λ c = 76 nm 131 MeV, λ c = 210 nm 78 MeV, λ c = 976 nm 37 MeV, λ c = 9533 nm Blackbody 3000 K 1 10 100 1000 10000 100000 Wavelength λ (nm)
NIST/DARPA EUV Reflectometry facility Beamline 7 1989, Early work begun 1993, New monochromator commissioned 1992-1997, over 100 measurements/year 1998-1999, SURF II - SURF III upgrade 2000, installation of new sample chamber 2003, over 150 measurements
NIST/DARPA EUV Sample Chamber Samples up to: 40 cm diameter 40 kg mass Wavelength 3-35 nm Demonstrated accuracy Better than 1% (2) EUV-sensitive photodiode detectors 2 hour pump-down time
Future Directions Cleanroom facility for sample handling/loading Upgrade monochromator to meet 0.006Å precision requirement for EUVL New detector scheme to reduce measurement overhead and improve sample alignment speed and precision Improved motion control
EUV Detector Radiometry Beamline Beamline 9 Wavelength Drive Grating Masks Exit Slit Monitor Diode Ionization Chamber Experiment al Chamber SURF III Radiation Gate Valve Ion Pump Ion Pump Grating Gate Valve Cryopump Ion Pump Manual Gate Valve System Capabilities: Intercompare Two Photodiodes Calibrate Photodiode vs. Ionization Chamber Transmission of Filters
Characteristics of Beamline 9 Wavelength range: 5-50 nm 100.0 Typical Diode Trace 0.30 Optical power: ~20 nw @13 nm absolute calibration with gas absorption crosssection Uncertainty of ~4% @13.6 nm (1σ) Si photodiode or Al 2 O 3 Quantum Efficiency (electron / photon) 10.0 1.0 0.1 10 100 Wavelength (nm) 0.25 0.20 0.15 0.10 0.05 0.00 Responsivity (A / W)
Absolute Cryogenic Radiometer- Based Diode Calibrations ACR Liquid He DUT Transfer optics EUV beam
ACR-based diode calibrations 5 0.30 ACR-Based Responsivty Measurements Measured responsivity (A/W) 0.25 0.20 0.15 0.10 0.05 uncoated detector Ti-Zr-C coated detector 0.00 10 15 20 25 30 35 Wavelength (nm)
Flying Circus Measurements FC2 Working standard Transfer optics Aperture EUV beam
EUV Radiometry With Pulsed Sources Working Standard Condenser ML mirror beamsplitter Plasma Condenser Normalization Detector Gas Target Q-switched Nd:YAG laser, 10 ns pulse length;800 mj / pulse at 1064 µm, 400 mj / pulse at 532 nm 1 Hz pulsed valve. Kr gas emits ~40 µj/sr EUV emission has a duration of ~10 ns. LN 2 cooling available Xe to be added soon
Calibration of small EUV detector packages Working Standard DUT ML mirror beamsplitter Plasma Condenser Normalization Detector Imaging Optics Plasma is at the focus of a grazing-incidence Rh-coated parabolic collimating mirror Collimated beam is split into two arms by a 45 multilayer beamsplitter In each arm, collimated beam is refocused (1:1 image) on the detector Working Standard Charge (nc) Percent of points 40 35 30 25 20 15 10 5 Integrated Charge Normalization y = 0.0472480052 + 0.58395039x R= 0.99907297 0 0 10 20 30 40 50 60 70 Normalizer Charge (nc) Integrated Charge Residual 12 10 8 6 4 2 0 σ = 1.5% -2-0.1-0.05 0 0.05 0.1 Normalized Residual
FC2 Flying Circus calibration Normalization detector EUV beam Working standard Line-of-sight block Mo/Si mirror
Long term EUV mirror exposures Beamline 1 Dedicated beamline for illumination of Mo/Si multilayer samples with EUV radiation. In-situ reflectivity & sample photoemission measurement Spot size:600 µm x 850 µm (FWHM) 4.5 mw average power (in-band) Exposures in H 2 O atmosphere (upgrading to include additional atmospheres) Exposure times of 10 hours per day (160 J total fluence)
Beamline 1: Optical Configuration Beamline 1 H 2 O atmosphere Detector Input beam from SURF III Focusing mirror Sample chamber Mo/Si Multilayer sample Be window Calculated spectrum at sample Mo/Si Multilayered focusing mirror Beam path 1 0.8 Intensity (au) 0.6 0.4 0.2 0 120 125 130 135 140 145 wavelength (Angstroms)
1.05 EUV Endurance Testing Results Reflectivity degradation over time 10 Photoemission Over Time 1 8 Normalized Reflectivity 0.95 0.9 0.85 12 Hr. Control Si-capped 12 Hr H 2 O Si-capped 60 Hr H 2 O Ru-capped 60 Hr H 2 O Normalized Photoemission 6 4 12 Hr Control 12 Hr H 2 O Si-capped 60 Hr H 2 O Si-capped 60 Hr H 2 O Ru-capped 0.8 2 0.75 0 200 400 600 800 1000 Fluence (J) 0 0 200 400 600 800 1000 Fluence (J) Part of this work was performed under the auspices of the U.S. Department of Energy by University of California Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48. Funding was provided by the Extreme Ultraviolet Limited Liability Corporation under a Cooperative Research and Development Agreement.
Summary EUV Reflectometry EUV detector calibration Synchrotron-based LPP-based Detector packages Long-term EUV optics testing