Rutherford Backscattering & Secondary Ion Mass Spectrometery

Advanced Materials Characterization WorkshopJune 3 and 4, 2013

University of Illinois at Urbana-Champaign | Materials Research Laboratory

Timothy P. Spila, Ph.D.

Frederick Seitz Materials Research LaboratoryUniversity of Illinois at Urbana‐Champaign

Rutherford Backscattering Spectrometry

RBS is an analytical technique where high energy ions (~2 MeV)are scattered from atomic nuclei in a sample. The energy of theback-scattered ions can be measured to give information onsample composition as a function of depth.

Geiger‐Marsden Experiment

Top: Expected results: alpha particles passing through the plum pudding model of the atom undisturbed.

Bottom: Observed results: a small portion of the particles were deflected, indicating a small, concentrated positive charge.

Rutherford Backscattering Spectrometry

2 MeV Van de Graaff accelerator

beam size Φ1-3 mmflat samplecan be rotated

Primary Beam Energy

thin film projected on to a plane: atoms/cm2

Figure after W.‐K. Chu, J. W. Mayer, and M.‐A. Nicolet, Backscattering Spectrometry (Academic Press, New York, 1978).

(Nt)[at/cm2] = N[at/cm3] * t[cm]

1 keV 1 MeV(log E)

1 keV 1 MeV

Elastic Two‐Body Collision

22 22 sin cost i i

MMMKM M

E1 = KEo

M1<M2, 0 ≤θ≤180o

RBS: He backscatters from M2>4

0 ≤Φ≤90o

0 50 100 150 2000.0

= 150o

Target mass (amu)

M1vo2 = M1v1

2 + M2v22

M1vo = M1v1 + M2v2

Elastic Scattering

Rutherford Scattering Cross Section

2 241 2 21

2( , ) sin ( ) 2( )

4 2RZ Z ZME ME E

Coulomb interaction between the nuclei:exact expression -> quantitative method

Electron Stopping

Figure after W.‐K. Chu, J. W. Mayer, and M.‐A. Nicolet, Backscattering Spectrometry (Academic Press, New York, 1978).

1 MeV(log E)

RBS – Simulated Spectra

Element (Z,M): O(8,16), Al(13,27), Ti(22,48), In(49,115), Au(79,197)

hypothetical alloy Au0.2In0.2Ti0.2Al0.2O0.2/C

C10 ML 100 ML Au

TiAlOC

1200 8000

TiAlOC

1000 ML16000

22( , )R

0 50 100 150 2000.0

= 150o

Target mass (amu)

4000 ML 10000 ML20000 50000

SIMNRA Simulation Program for RBS and ERD

Thickness Effects

Series 0Series 1

Channel700650600550500450400350300250200150100500

11,500

11,000

10,500

10,000

100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500

Energy [keV]

N surface

300 nm

Ti surfaceTi interface

N, O, Mginterface

Series 0Simulated

Channel700650600550500450400350300250200150100500

14,000

13,000

12,000

11,000

10,000

100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500

Energy [keV]

Ti surface

400 nm

Ti interface

N, O, Mginterface

N surface

Series 0Simulated

Channel700650600550500450400350300250200150100500

14,000

13,000

12,000

11,000

10,000

100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500

Energy [keV]

600 nm

Ti surface

Ti interface

N, O, Mginterface

N surface

TiN/MgO

DScattered

Incident

Incident Angle Effects

TiN/MgO

Series 0Simulated

Channel700650600550500450400350300250200150100500

14,000

13,000

12,000

11,000

10,000

100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500

Energy [keV]

Ti surface400 nm

Ti interface

N, O, Mginterface

N surface

Series 0Simulated

Channel700650600550500450400350300250200150100500

100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500

Energy [keV]

400 nm

N surface

Ti surface

Ti interface

N, O, Mginterface

Scattered

Incident

Surface peaks do not change position with incident angle;

Example: Average Composition

I. Petrov, P. Losbichler, J. E. Greene, W.-D. Münz, T. Hurkmans, and T. Trinh, Thin Solid Films, 302 179 (1997)

RBS: Oxidation Behavior

TiN/SiO2

Annealed in atmosphere for 12 min at Ta = 600 °C

As-deposited

Experimental spectra and simulated spectra by RUMP

RBS Summary

DScattered

Incident

• Quantitative technique for elemental composition• Requires flat samples; beam size Φ1‐3 mm• Non‐destructive• Detection limit varies from 0.1 to 10‐6, depending on Z

•optimum for heavy elements in/on light matrix, e.g. Ta/Si, Au/C…• Depth information from monolayers to 1 m

Secondary Ion Mass Spectrometry

SIMS is an analytical technique based on themeasurement of the mass of ions ejected from a solidsurface after the surface has been bombarded withhigh energy (1‐25 keV) primary ions.

Primary Ions Secondary Ions

Technique Comparison

Block Diagram of SIMS Technique

Comparison of Static and Dynamic SIMS

TECHNIQUE DYNAMIC STATICFLUX ~1017 ions/cm2

(minimum dose density)< 1013 ions/cm2

(per experiment)

INFORMATION Elemental Elemental + Molecular

SENSITIVITY < 1 ppm(ppb for some elements)

TYPE OF ANALYSIS Depth ProfileMass Spectrum3D Image Depth Profile

Surface Mass Spectrum2D Surface Ion Image

SAMPLING DEPTH 10 monolayers 2 monolayers

SPATIAL RESOLUTION

Cameca ims 5fProbe mode: 200 nmMicroscope mode: 1 m

PHI TRIFT III0.1 m

SAMPLE DAMAGE Destructive in analyzed area –up to 500 m per area

Minimal

Magnetic Sector Mass Spectrometer

CAMECA ims 5f

PRIMARY ION COLUMN

SECONDARY ION COLUMN

Time of Flight Mass Spectrometer

Physical ElectronicsTRIFT III TOF-SIMS

Sample

Cs+ or O2+

Pre‐Spectrometer Blanker

ContrastDiaphragm

EnergySlit

Post‐SpectrometerBlanker

ESA 2ESA 3

21 mveV

Ion Beam Sputtering

Sputtered species include:• Monoatomic and polyatomic particles of sample material (positive, negative or neutral)• Resputtered primary species (positive, negative or neutral)• Electrons• Photons

MD Simulation of ion impact

Enhancement of Sputtering Yields due to C60 vs. Ga Bombardment of Ag{111} as Explored by Molecular Dynamics Simulations, Z. Postawa, B. Czerwinski, M. Szewczyk, E. J. Smiley, N. Winograd and B. J. Garrison, Anal. Chem., 75, 4402-4407 (2003).

Animations downloaded from http://galilei.chem.psu.edu/sputtering-animations.html.

Quantitative Surface Analysis: SIMS

In SIMS, the yield of secondary ions is strongly influenced by the electronic state of the material being analyzed.

Ism = secondary ion current of species m

Ip = primary particle fluxym = sputter yield+ = ionization probability to positive ionsm = factional concentration of m in the layer = transmission of the analysis system

mmpms yII

Total Ion Sputtering Yield

First principles prediction of ion sputter yields is not possible with this technique.

Courtesy of Prof. Rockett

Sputter yield: ratio of number of atoms sputtered to number of impinging ions, typically 5-15

Ion sputter yield: ratio of ionized atoms sputtered to number of impinging ions, 10-6 to 10-2

Ion sputter yield may be influenced by:•Matrix effects•Surface coverage of reactive elements•Background pressure in the sample environment•Orientation of crystallographic axes with respect to the sample surface•Angle of emission of detected secondary ions

Effect of Primary Beam on Secondary Ion Yields

Oxygen bombardmentWhen sputtering with an oxygen beam, the concentration of oxygen increases in the surface layer and metal-oxygen bonds are present in an oxygen-rich zone. When the bonds break during the bombardment, secondary ion emission process, oxygen becomes negatively charged because of its high electron affinity and the metal is left with the positive charge. Elements in yellow analyzed with oxygen bombardment, positive secondary ions for best sensitivity.

Cesium bombardmentWhen sputtering with a cesium beam, cesium is implanted into the sample surface which reduces the work function allowing moresecondary electrons to be excited over the surface potential barrier. With the increased availability of electrons, there is more negative ion formation. Elements in green analyzed with cesium, negative secondary ions for best sensitivity.

Graphics courtesy of Charles Evans & Associates web sitehttp://www.cea.com

Relative Secondary Ion Yield Comparison

From Storms, et al., Anal. Chem. 49, 2023 (1977).

Relative Secondary Ion Yield Comparison

From Storms, et al., Anal. Chem. 49, 2023 (1977).

Determination of RSF Using Ion Implants

CdIIdCtIRSF

LevelProfile:

GaussianProfile:

RSF = Relative Sensitivity FactorIm, Ii = ion intensity (counts/sec) = atom density (atoms/cm3) = implant fluence (atoms/cm2)

mmpms yII

C = # measurement cyclest = analysis time (s/cycle)d = crater depth (cm)Ib = background ion counts

Where:

Positive and Negative Secondary Ions

0 100 200 300 400 500 600 70010-1

Ion implanted P standard

O+2 beam

Cs+ beam Si P

Depth (nm)0 100 200 300 400 500 600 700

1023 Ion implanted P standard

O+2 beam

Cs+ beam Si P

Depth (nm)

Definition of Mass Resolution

Graphic courtesy of Charles Evans & Associates web sitehttp://www.cea.com

Mass resolution defined by m/mMass resolution of ~1600 required to resolve 32S from 16O2

Depth Profile Application with Hydrogen

Detects hydrogen Large dynamic range

Isotopic Analysis

0 50 100 150 200 250 300 350Sputter Time (min.)

Ni Al3NiO, NiAl O , Al O 42 32NiOO

Ni Al 600 C: 4 h 18O , 16 h 16O3 2 2R.T. Haasch, A.M. Venezia, and C.M. Loxton. J. Mater.Res., 7, 1341 (1992).

(a) AES composition depth profile(b) SIMS isotopic oxygen diffusion profile expressed as a

percentage of the total oxygen(c) Schematic of layered oxide structure

(a) (b)

M16OM18O

B Depth Profile in Si(001)

SIMS depth profiles through a B modulation-doped Si(001):B film grown by GS-MBE from Si2H6and B2H6 at Ts=600 °C. The incident Si2H6 flux was JSi2H6 = 2.2x1016 cm-2 s-1 while the B flux JB2H6 was varied from 8.4x1013 to 1.2x1016 cm-2 s-1. The deposition time for each layer was constant at 1 h.

G. Glass, H. Kim, P. Desjardins, N. Taylor, T. Spila, Q. Lu, and J. E. Greene. Phys. Rev. B, 61,7628 (2000).

Depth Resolution and Ion Beam Mixing

SIMS depth profiles through a B -doped layers in a Si(001) film grown by GS-MBE from Si2H6 at TS=700 °C. The Si2H6, flux, JSi2H6, was 5X1016 cm-2 s-1 while the B2H6flux, JB2H6 varied from 0.16-7.8X1014 cm-2 s-1. The inset shows the two-dimensional B concentration NB

2D as a function of JB2H6.

Q. Lu, T. R. Bramblett, N.-E. Lee, M.-A. Hasan, T. Karasawa, and J. E. Greene. J. Appl. Phys. 77, 3067 (1995).

Static and Dynamic SIMS

Dynamic SIMS Static SIMS

•Material removal•Elemental analysis•Depth profiling

•Ultra surface analysis•Elemental or molecular analysis•Analysis complete before significant fraction of molecules destroyed

Courtesy Gregory L. Fisher, Physical Electronics

Extreme Mass Range

0 2000 4000 6000 8000010

n)Integral: 1922 TG_SCAN03_NEGSEC_AU2_22KV_BUNCHED_2NA_400UM_90MIN_CDOUT_CHGCOMP_0-10000AMU.TDC - Ions 400µm 17452848 cts

256015762166

118217731379

985394

Mass (amu)

Trace AnalysisGaAs Wafer

85.85 85.90 85.95 86.00Mass [m/z]

GaNH3m/m = 11,600

Si Wafer

38.94 38.96 38.98 39.00 39.02 39.04Mass [m/z]

No sputtering to remove organics on surface.Large C3H3 peak does not have a tail to lower mass which would obscure C2HN and K.

InAs/GaAs Quantum Dots

In+ Linescans of Quantum Dots

µm0 0.5 1.0 1.5 2.0

µm0 0.5 1.0 1.5

µm0 0.5 1.0 1.5 2.0 2.5 3.0 3.5

Cts: 550893; Max: 36; Scale: 1µm

GaAs/AlGaAs Depth Profile

Analysis beam: 15kV Ga+

Sputter Beam: 300V O2+

with oxygen flood

200 400 600 800 1000Time (Seconds)

Total_Ion

200 400 600 800 1000Time (Seconds)

Total_Ion

Depth Profile Beam Alignment

TOF‐SIMS Imaging of Patterned Sample

O h(nm)

Courtesy Josh Ritchey, Audrey Bowen, Ralph Nuzzo and Jeffrey Moore, University of Illinois

400 mS

400 mBr

50 mBr

TOF‐SIMS Ion Images of an Isolated NeuronFirst Images of Vitamin E Distribution in a Cell

Courtesy E.B. Monroe,J.C. Jurchen, S.S. Rubakhin,J.V. Sweedler. University ofIllinois at Urbana-Champaign

TOF‐SIMS Ion Images of Songbird Brain

Selected ion images from the songbird brain. Each ion imageconsists of ~11.5 million pixels within the tissue section and isthe combination of 194 individual 600m×600m ion imagesprepared on the same relative intensity scale. Ion images are(A) phosphate PO3− (m/z 79.0); (B) cholesterol (m/z 385.4);(C) arachidonic acid C20:4 (m/z 303.2); (D) palmitic acidC16:0 (m/z 255.2); (E) palmitoleic acid C16:1 (m/z 253.2); (F)stearic acid C18:0 (m/z 283.3); (G) oleic acid C18:1 (m/z281.2); (H) linoleic acid C18:2 (m/z 279.23); and (I) -linolenicacid C18:3 (m/z 277.2). Scale bars = 2 mm.

Courtesy Kensey R. Amaya, Eric B. Monroe, Jonathan V. Sweedler, David F. Clayton. International Journal of Mass Spectrometry 260, 121 (2007).

Diamond‐Like‐Carbon Friction Testing

wear tracks and scars formed on DLC‐coated disk and ball sides during test in dry oxygen

DLC coated ball

DLC coated disk

Oxygen Carbon C + O Overlay

Courtesy O.L. Eryilmaz and A. ErdemirEnergy Systems Division, Argonne National Laboratory Argonne, IL 60439 USA

3‐D TOF‐SIMS imaging of DLCWear track from hydrogenated DLC tested in dry nitrogenCourtesy O.L. Eryilmaz and A. ErdemirEnergy Systems Division, Argonne National Laboratory Argonne, IL 60439 USA

3‐D TOF‐SIMS Movies of DLC

H CH C2H C2H2O

NFC6 H2 Environment TOF-SIMS ImagesCourtesy O.L. Eryilmaz and A. ErdemirEnergy Systems Division, Argonne National Laboratory Argonne, IL 60439 USA

SIMS Summary

Probe/Detected Species InformationSurface Mass Spectrum2D Surface Ion ImageElemental Depth Profiling3D Image Depth Profiling

Elements DetectableH and above

Sensitivityppb - atomic %

Analysis Diameter/Sampling Depth~1 m - several mm/0.5 - 1nm

Acknowledgments

Rutherford Backscattering & Secondary Ion Mass Spectrometery

Documents

Rutherford Appleton Laboratory Remote Sensing Group Tropospheric ozone retrieval from uv/vis spectrometery RAL Space - Remote Sensing Group Richard Siddans,

Double scattering in grazing angle Rutherford backscattering … · 2018. 3. 7. · One must also take care when deciding which paths to consider. The Rutherford cross section is

Rutherford Backscattering Spectrometry Analysis of Self ... · Rutherford Backscattering Spectrometry Analysis of Self-Formed Ti-Rich Interface Layer Growth in Cu(Ti)/Low-k Samples

Rutherford Backscattering Spectrometry (RBS) - ICTPusers.ictp.it/~pub_off/lectures/lns022/Mayer_1/Mayer_1.pdf · Abstract Rutherford Backscattering Spectrometry (RBS) is a widely

Rbs – rutherford backscattering spectrometry

8 T/ CRADA RUTHERFORD/67531/metadc... · Rutherford Backscattering Spectrometry (RBS) has the advantage to allow a non-destructive and accurate depth profiling over a few thousand

Analysis of Oxidation Behavior in Nanocrystal …...Analysis of Oxidation Behavior in Nanocrystal -FeSi2 /Si Composites by Rutherford Backscattering Spectrometry and Computation of

STOICHIOMETRIC, OPTICAL AND STRUCTURAL PROPERTIES ... · The measurement using the Rutherford backscattering spectrometry was performed using the 4He+ ion beam and the incident energy

Modern Methods in Heterogeneous Catalysis Research · Rutherford backscattering spectrometry Characteristic: Sample type: thin films and bulk solids Depth information: 2μm Latheral

Interaction of europium and nickel with calcite studied by ... · Interaction of europium and nickel with calcite studied by Rutherford Backscattering Spectrometry and Time-Resolved

RUTHERFORD BACKSCATTERING ANALYSIS OF THE FAILURE …

Research Article Rutherford Backscattering Spectrometry …downloads.hindawi.com/archive/2015/215210.pdf · 2019-07-31 · Research Article Rutherford Backscattering Spectrometry

Supporting Information - Royal Society of Chemistry5.2 Rutherford Backscattering Spectrometry Full spectrum A typical spectrum acquired for 6 Mev alpha-particles scattered (detection

Rutherford Backscattering Spectrometry Timothy P. Spila, Ph.D

Backscattering TMS

RBS - Rutherford Backscattering Spectrometryindico.ictp.it/event/a0268/session/40/contribution/25/material/0/0.pdf · RBS - Rutherford Backscattering Spectrometry ... Computer code

Reduction of Dichlorosiliane-Based Tungsten Silicide Resistivity … · 2019. 4. 29. · and 4 sccm, respectively. By Rutherford backscattering spectroscopy (RBS)10 it was found that

ll 97th Meeting,/67531/metadc620220/m2/1/high_re… · composition, as determined by Rutherford Backscattering and Proton Induced Gamma Emission, was Li3.3P03.8N0.24; the N content

2. RUTHERFORD BACKSCATTERING SPECTROMETRY Basic Principles

in Nitrogen-Implanted Silicon Carbide/67531/metadc623586/m2/1/high_res... · conducted for compositional analysis of the as-implanted surface. Rutherford backscattering spectroscopy