PTB's Synchrotron radiation based metrologyPTB s Synchrotron radiation based metrology

Christian Laubisworking group EUV radiometryworking group EUV radiometry

PTB ‐the National Metrology Institute

About PTB:

PTB the national metrology institutePTB – the national metrology institute providing scientific and technical services

What are PTB's capabilities?

PTB measures with the highest accuracyand reliability – metrology as the corecompetence

www ptb dewww.ptb.de

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PTB @ BESSY I, II, MLS

1982 – 1999: BESSY I BESSY II:circumference 250 m

PTB:

circumference 250 m electron energy 1.7 GeV

since 1999: BESSY II 10 beamline branchesfrom 400 nm (3 eV)

to 0.02 nm (60 keV)

UV X‐ray

Metrology Light Source MLSi f 48

EUV

since 2008: MLS 

8 beamlines

circumference 48 m electron energy 100 ‐ 630 MeV

8 beamlinesfrom 8 mm

to  4 nm (300 eV)

UVUV

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THz EUVUV

Methods

‐ Source calibrationSource calibration

‐ Detector calibration

‐ X‐ray fluorecence analysis

L thi k d t i ti‐ Layer thickness determination

‐ EUV Reflectometry

‐ EUV Scatterometry

‐ EUV Exposures

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EUV ReflectometryEUV Reflectometry

EUV  Beamline

EUV – beamline: Spot size

wavelength range 5.5 nm to 48 nm

4‐blade aperture at intermediate focus imaged onto sample position

4 4 2 1 1 2 0 1 0 1 24 x 4 mm2

measured spot size at sample position

1 x 1 mm2 0.1 x 0.1 mm2

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Optics for EUV Sources

5 sr collector, 670 mm outer diameterdesigndesign

coatingmounted for measurements at PTB

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mounted for measurements at PTB

EUV ReflectometryEUV Reflectometry

Soft X‐ray  Beamline

Soft X‐ray radiometry beamline at BESSY II

wavelength range 1 nm to 25 nm

EUV ellipso‐scatterometer

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EUV ellipso‐scatterometer

EUV‐Ellipso‐Scatterometer

linear polarization analyzer

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Selectivity of Brewster‐analyser 

Polarisation effects at EUV reticles

“horizontal  lines“ “vertical lines“

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V. Soltwisch, et al., Proc. SPIE 9422 9422‐38 (2015)

Reflectometry: optical constants

EUV photomask absorber stack

substrate Si, SiO2‐buffer, TaN absorber, ARCsubstrate Si, SiO2 buffer, TaN absorber, ARC

optical constants determined from subsequently deposited SiO2, TaN, and ARC layers

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data of Henke shown for comparison

Irradiation and Exposure experimentsIrradiation and Exposure experiments

Irradiation beamline: Experimental chamber

Experimental chamberExperimental chamberwith gas supply systemand load lock

Gases available: H2 and others, 5 Pa total pressure5 Pa total pressurecan be handled bydifferential pumping

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Irradiation beamline: Spectral distribution

blue dashes:  spectrum after mirrorred line:  with additional Si  filter

integral power :  0.9  W (no filter)        2.5 nJ / pulse0.15 W (Si‐Filter) 0.4 nJ / pulse

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Power density and spatial distributionclose focus

20 W/cm2 on 0.1 mm x 0.3 mm hot spot

Power densityfor different distances from focus.

standard focusTwo scalings eachfor best depiction of'Hot spot' and 'Cold spot'.p p

21 W/cm2 on 2.5 mm x 1.5 mm cold spot

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EUV ScatterometryEUV Scatterometry

EUV Scatterometry

Scheme of scatterometry measurements

geometrical properties:• structure width• structure height

measurements

test pattern: • structure height• edge angles • edge profiles 

p

semi‐dense bright linesCD 180 nm, duty cycle 1:3

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• …..

Comparison: Scatterometry vs. AFM

CDblue: scatterometry,  red: AFMoffset scatterometry:  ‐2.7(18) nm

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The Community

262nd PTB Seminar EUV metrology Oct. 2011

273rd PTB Seminar VUV and EUV metrology Oct. 2013

290st PTB Seminar VUV and EUV metrology Nov. 2015 www.euv2015.ptb.de

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290 PTB Seminar VUV and EUV metrology Nov. 2015                www.euv2015.ptb.de

Thank you for your attention

www.euv2015.ptb.de

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