I PB X-ray and IR spectrometry Reference-free XRF and GIXRF - PowerPoint PPT Presentation

I PB X-ray and IR spectrometry Reference-free XRF and GIXRF analysis Burkhard Beckhoff Physikalisch-Technische Bundesanstalt Abbestraße 2-12, 10587 Berlin, Germany Joint ICTP-IAEA School on Novel Experimental Methodologies for Synchrotron Radiation Applications in Nano-science and Environmental Monitoring Trieste, Italy, November 17-28, 2014

I PB Outline X-ray and IR spectrometry analytical challenges for nanotechnologies reference-free x-ray spectrometry surface contamination and nanolayer characterization depth profiling at grazing incidence chemical speciation at buried interfaces towards in-situ speciation of bulk-type films high-resolution spectrometry

I PB Analytical challenges for nanotechnologies X-ray and IR spectrometry dozens of new nanoscaled materials appear every month technology R&D cycles for new materials down to 4 months need for correlation of material properties with functionality requirements on sensitivity, selectivity and information depth most analytical methodologies rely on reference materials or calibration standards but there are only few at the nanoscale usage of calibrated instrumentation and knowledge on atomic data enables reference-free techniques such as SR based XRS

Challenges for nanotechnologies I PB nano-scaled reference materials X-ray and IR spectrometry Nanoscaled Reference Materials ( in line with ISO/TC 229 Nanotechnologies ) materials are the key to guaranteeing realiability and correctness for results of chemical analyses and technical measurements Categories: Every month several tens new flatness nanoscaled materials appear. film thickness single step , periodic step, step grating The number of nanoscaled reference lateral X-Y-axis, 1-dim materials is considerably lower. lateral X-Y-axis, +2-dim, critical dimensions 3-dimensional Reference-free / first principles nanoobjects/nanoparticles/nanomaterial based methodologies can address nanocrystallite materials this increasing gap. porosity depth profiling resolution www.nano-refmat.bam.de/en/

X-ray spectrometry methodologies: I PB reference-based versus reference-free approaches X-ray and IR spectrometry reference material related technique based on well known calibration specimens or reference materials unknown detection efficiency unknown spectral unknown response functions distribution and / or unknown intensity d fluorescence radiation calibration specimen specimens compensation for laboratory instruments missing knowledge

X-ray spectrometry methodologies: I PB reference-based versus reference-free approaches X-ray and IR spectrometry reference material related technique reference-free technique XRF excitation channel based on well known calibration based on calibrated instrumen- specimens or reference materials tation and fundamental parameters unknown detection efficiency absolute detection efficiency unknown spectral unknown response functions and response functions distribution and / or known spectral unknown intensity d d distribution and known intensity fluorescence fluorescence radiation radiation calibration fundamental specimen specimen specimens parameters knowledge of compensation for well-known laboratory instruments the parameters missing knowledge synchrotron radiation

I PB Synchrotron radiation based x-ray spectrometry X-ray and IR spectrometry XRS excitation channel: XRS detection channel: XRF excitation channel XRF detection channel absolute detection efficiency and response functions well-known spectral distribution well-known derived from and a well-known radiant power solid angle d x-ray radiometry fluorescence radiation PTB capabilities: characterized beamlines fundamental parameters specimen knowledge of atomic parameters calibrated photodiodes (EMRP IND07, NEW01; EXSA) calibrated diaphragms transmission measurements absorption correction factors calibrated Si(Li) detectors JAAS 23 , 845 (2008)

I PB Determination of L-shell photoionization cross sections X-ray and IR spectrometry

I PB Determination of L-shell photoionization cross sections X-ray and IR spectrometry Comparison of different PCS data for Mo Phys. Rev. Lett 113 , 163001 (2014)

I PB Determination of L-shell photoionization cross sections X-ray and IR spectrometry Response function based deconvolution of a Mo layer XRF spectrum for each L-shell. Experimentally determined PCS for the Mo-L subshells and the comparison to calculated data. Phys. Rev. Lett 113 , 163001 (2014)

Tuning the analytical sensitivity and information depth I PB by means of appropriate operational parameters X-ray and IR spectrometry excitation conditions total-reflection tunable incident angle tunable photon energy tunable incident angle total-reflection tunable incident angle tunable photon energy E 0 = photon energy of excitation radiation XSW = X-ray Standing Wave field E 1 = photon energy above absorption edge JAAS 23 , 845 (2008) E f = photon energy of fluorescence radiation

How can a method (rows) help another method I PB (columns) to improve or complement the results X-ray and IR spectrometry Methods TXRF GIXRF XRF XRR XRD GISAXS information on information on information on surface nanoparticle TXRF surface surface surface contamination composition contamination contamination contamination absolute angle validation near surface near surface depth nanoparticle GIXRF calibration measurands depth profiles profiles composition information on information on validation validation nanoparticle XRF material material measurands measurands composition composition composition layer thickness layer thickness contaminations/ layer thickness, substrate surface XRR and roughness for and roughness spectral diffrac- roughness, density layer modelling for modelling tion artefact information on information on information on information on information on XRD material morpho- material morpho- material morpho- material material logy, artefacts logy, artefacts logy, artefacts morphology morphology particle size particle size particle size particle size GISAXS _____ distribution distribution distribution distribution J. Anal. At. Spectrom. 28, 549 (2013)

Typical characteristics and properties of I PB x-ray analytical and metrology techniques X-ray and IR spectrometry TXRF GIXRF XRF XRR XRD GISAXS nano nanolayers, elemental structured Applications surfaces depth profiles, bulk materials nano layers thin layers surfaces, thin implantation profiles films layer mass density, mass density in mass density in the Properties to be thickness, layer thickness, concentration, depth the range of the range of the elements particle size profile in the range of elements B to measured roughness, orientation B to U the elements B to U U density app.10 13 atoms/ 3 wgt.%, app.10 12 atoms/ cm 2 app.10 10 atoms/ cm 2 Detection limit 2 nm 5 nm 2 nm cm 2 2 nm 10 10 atoms/ cm 2 - 10 12 atoms/ cm 2 - 10 17 0.1 nm 10 Range ppb % 5- 500 nm 2 nm 1µm 10 15 atoms/ cm 2 atoms/ cm2 nm Accuracy (and 0.15* / 0,05 0.2*/0.05 0.2*/0.05 0.02 0.05 0,.15 reproducibility ) (0.02) (0.03) (0.03) (0.01) (0.02) (0.02) (*reference free) 0.5 mm 2 -0.5 0.5 mm 2 -0.5 1 mm 2 -1 cm 2 0.5 mm 2 -0.5 cm 2 to 1 mm 2 to 1 mm 2 Spatial resolution cm 2 cm 2 Measurement 10 50 s 1000 s/ pt 2000 s 5 h 100 s 1000 s 1000 s 5 h 1000 s 5 h speed min/frame J. Anal. At. Spectrom. 28, 549 (2013)

Novel XRS instrumentation for advanced materials I PB characterizations with synchrotron radiation X-ray and IR spectrometry PTB XRS intrumentation at BESSY 9-axis manipulator and chamber ensuring the entire TXRF, GIXRF and XRF regime polarization-dependent speciation by XAFS combined GIXRF and XRR investigations movable aperture system for reference-free XRF and atomic FP determinations Transfer of modified instrumentation to TU Berlin for a laboratory plasma source LNE/CEA-LNHB for SOLEIL storage ring IAEA (UN) for ELETTRA storage ring Janin Lubeck et al., Rev. Sci. Instrum. 84 , 045106 (2013) .

I PB Quantitation in SR-TXRF routine analysis on Si wafers X-ray and IR spectrometry spin-coated wafer with 10 12 cm -2 of various transition metals TXRF spectra deconvolution including Si(Li) detector response functions, RRS, and bremsstrahlung contributions. reference-free TXRF quantitation : known incident flux, detector efficiency and solid angle. Phys. Stat. Sol. B 246 ,1415 (2009)

I PB Reference-free quantitation in SR-TXRF analysis X-ray and IR spectrometry mass deposition m i / F I of the element i with unit area F I m P 1 i i ln 1 F 1 1 P Q det I tot , i 0 , Wsurf i , E 4 sin 0 , in tot i photon energy of the incident (excitation) radiation E 0 radiant power of the incident radiation P S 0 0 diode , E 0 signal of the photodiode measuring the incident radiation S 0 spectral responsitivity of the photodiode diode , E 0 Analytical Chemistry 79 , 7873 (2007)