2015-2 joint ictp/iaea workshop on advanced simulation and...
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2015-2
Joint ICTP/IAEA Workshop on Advanced Simulation and Modellingfor Ion Beam Analysis
C. Jeynes
23 - 27 February 2009
University of Surrey Ion Beam CentreU.K.
IBA IV IAEA Intercomparison
Ion Beam Centre
www.surreyibc.ac.ukIBA IV: IAEA Intercomparison
The IAEA Intercomparison of IBA codes
Joint ICTP/IAEA Workshop on Advanced Simulation and Modelling for Ion Beam Analysis
23 - 27 February 2009, Miramare - Trieste, Italy
Chris JeynesUniversity of Surrey Ion Beam Centre
Guildford, EnglandMonday February 23rd 2009
Ion Beam Centre
www.surreyibc.ac.ukIBA IV: IAEA Intercomparison
IAEA-sponsored intercomparison of IBA software codes
Nuno P. Barradas (Instituto Tecnológico e Nuclear & University of Lisbon)Kai Arstila (Katholieke Universiteit Leuven)Gabor Battistig (MFA Budapest)E. Kótai & Edit Szilágyi (KFKI Budapest) Marco Bianconi & G. Lulli (CNR-IMM Bologna)Nick Dytlewski (IAEA, Vienna)Chris Jeynes (University of Surrey Ion Beam Centre)Matej Mayer (Max-Planck-Institut Garching)Eero Rauhala (University of Helsinki)Mike Thompson (Cornell University New York)
Nuclear Instruments and Methods B262 (2007) 281-303summary at: Nuclear Instruments and Methods B266 (2008) 1338-1342
This talk was presented at the IBA conference in Hyderabad, September 2007
http://www.mfa.kfki.hu/sigmabase/ibasoft/
Ion Beam Centre
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Context
• Status of software for Ion Beam Analysis in Materials Development, NAPC/PS/2002/F1.TM - 25886, (IAEA, Vienna 2003)
• E. Rauhala, N.P. Barradas, S. Fazinić, M. Mayer, E. Szilágyi, M. Thompson, Status of ion beam data analysis and simulation software, Nucl. Instr. Meth. B244 (2006) 436
• Barradas & Rauhala chapter on IBA Software in new IBA Handbook (this has been circulated on ION)
• IAEA cross-section CRP: A. Gurbich, I. Bogdanovic-Radovic, M. Chiari, C. Jeynes, M. Kokkoris, A.R. Ramos, M. Mayer, E. Rauhala, O. Schwerer, Shi Liqun and I. Vickridge, Status of the problem of nuclear cross section data for IBA, Nucl. Instrum. Methods Phys. Res., Sect. B, 266(2008)1198-1202
• PIXE & PIGE not considered here
Ion Beam Centre
www.surreyibc.ac.ukIBA IV: IAEA Intercomparison
• Ion Beam Analysis is an accurate and traceable technique• IBA is not trivial to calculate:
– The yield Ψe at detected energy E3 for an element e is given by the triple integral: (D.K.Brice, Thin Solid Films 19 1973, 121)
– Even in the single scattering approx. the calculation is intricate– Many physical effects to take care of
• New generation single scattering codes• Monte Carlo code available for comparison • IAEA persuaded of need for support (cf IAEA support of IBANDL, SigmaCalc)
Need for Intercomparison
Ion Beam Centre
www.surreyibc.ac.ukIBA IV: IAEA Intercomparison
Depth profiling codes
• First Generation Single Scattering Codes– Ziegler (1976)– GISA (Rauhala, 1984)– RUMP (Thompson, 1985)– RBX (Kótai, 1994)
• Straggling Code– DEPTH (Szilágyi, 1995)
• New Generation Single Scattering Codes– DataFurnace (“NDF” Barradas, Jeynes & Webb 1997) – SIMNRA (Mayer, 1997)
• Monte Carlo Code– MCERD (Arstila, 2000)
Ion Beam Centre
www.surreyibc.ac.ukIBA IV: IAEA Intercomparison
Overview of Intercomparison
1. Comparative simulations1. Baseline RBS (sanity check)
a) Screeningb) Pileupc) Double scattering
2. Channelling3. EBS with sharp resonances O(a,a)O: (3.04 MeV 4He) 4. ERD (1.5 MeV He)5. HI-RBS (3.5 MeV Li)6. HI-ERD (50 MeV I)7. NRA (1 MeV 3He)8. NRA (1 MeV D)
2. Detailed analysis of real spectra (RBS)1. a-Si spectrum (sanity check)2. IRMM certified Sb implant in Si 3. HfO/Si sample4. Co-Re multilayer sample (roughness)
Ion Beam Centre
www.surreyibc.ac.ukIBA IV: IAEA Intercomparison
Baseline Calculation
Simulation of 50nm Au/200nm SiO2/Si (1.5MeV 4He+, Bohr straggling, 16keV detector resolution, single pure Rutherford scattering, no pileup, SRIM 2003)
All codes: 0.3% agreement: yield & height
of various featuresSIMNRA, DataFurnace & RUMP:
0.1% yield & height agreementSurface & interface positions agree at 100eV
SIMNRA, DataFurnace:Edge widths agree at 500eV
0 500 1000 15000
5000
10000
15000
20000
Yiel
d (a
rb. u
nits
)
E (keV)
DEPTH GISA MCERD NDF RBX RUMP SIMNRA
Structure 1, Calculation 1
Theta=150Theta=15000
In=60In=6000, Out=30, Out=3000
Ion Beam Centre
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Simulation of 50nm Au/200nm SiO2/Si (1.5MeV 4He+, Bohr straggling, 16keV detector resolution, single Rutherford scattering with screening, no pileup, SRIM 2003)
Same as previous, but with L’Ecuyer and Andersen screening
Gold signal
SIMNRA & DataFurnaceindistinguishable, RUMP very close
1250 1300 135016000
17000
18000
17000
18000
a)Andersen screening:
NDF RUMP SIMNRA
No screening: NDF RUMP SIMNRA
Yiel
d (a
rb. u
nits
)
E (keV)
b)
Structure 1, Calculations 2 and 3
L'Écuyer screening: DEPTH NDF SIMNRA
No screening: (SIMNRA)
Yiel
d (a
rb. u
nits
)
Ion Beam Centre
www.surreyibc.ac.ukIBA IV: IAEA Intercomparison
Simulation of 50nm Au/200nm SiO2/Si (1.5MeV 4He+, Bohr straggling, 16keV detector resolution, single pure Rutherford scattering, pileup no PUR, SRIM 2003)
0 500 1000 1500
10
100
1000
10000
Structure 1, Calculation 7
Yiel
d (a
rb. u
nits
)
E (keV)
NDF RUMP SIMNRA SIMNRA without pileup
Same as previous but with pileup and no pileup rejection
SIMNRA & DataFurnace almost indistinguishable: difference due to slight variation in pileup treatmentRUMP very close
Ion Beam Centre
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Simulation of 50nm Au/200nm SiO2/Si (1MeV 4He+, Bohr straggling, 16keV detector resolution, screened Rutherford scattering, pileup, SRIM 2003, multiple & double scattering)
Same as previous, but with double scattering and pileup
SIMNRA & DataFurnacealmost indistinguishable
0 200 400 600 800 10001
10
100
1000
10000
100000
Structure 1, Calculation 26
NDF total DS
SIMNRA total DS
Yiel
d (a
rb. u
nits
)
E (keV)
Ion Beam Centre
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Simulation of Channelling
100% substitutional 66keV 1016 Ge/cm2 implant into bulk (100)Si; Si point defect distribution = Ge distribution but with 2% max concentration, Perfect (unreconstructed) surface
Only RBX
Comparison with Monte Carlo code BISIC is impressive
1250 1500 1750 20000.1
1
10
100
1000Structure 5, Calculation 28
random channelled RBX channelled BISIC
Yiel
d (a
rb. u
nits
)
E (keV)
BISIC:BISIC: E. Albertazzi, M. Bianconi, G. Lulli, R. Nipoti, M. Cantiano, NuE. Albertazzi, M. Bianconi, G. Lulli, R. Nipoti, M. Cantiano, Nucl. Instrum. cl. Instrum. MethodsMethods B118 (1996) 128B118 (1996) 128
Ion Beam Centre
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EBS with sharp resonances
Simulation of 50nm Au/200nm SiO2/Si 3.15 MeV 4He+, Bohr straggling, SigmaCalc cross-sections for O(α,α)O.
N.P. Barradas, E. Alves, C. Jeynes, M. Tosaki, Nucl. Instrum. N.P. Barradas, E. Alves, C. Jeynes, M. Tosaki, Nucl. Instrum. Methods B247 (2006) 381Methods B247 (2006) 381--389389A.F. A.F. GurbichGurbich, C. , C. JeynesJeynes, , NuclNucl. . InstrumInstrum. Methods B265 (2007) 447. Methods B265 (2007) 447--452452
3043keV resonance: 3043keV resonance: 10*Rutherford10*Rutherford
4% agreement between 4% agreement between SIMNRA, SIMNRA, DataFurnaceDataFurnace, , RUMP in region of sharp RUMP in region of sharp resonanceresonance
Significant algorithmic Significant algorithmic differences: differences: DataFurnaceDataFurnacealgorithm demonstrably algorithm demonstrably superiorsuperior
1000 1050 1100 11501000
1500
2000
2500
Structure 1, Calculation 16
DEPTH NDF RBX RUMP SIMNRA
Yie
ld (a
rb. u
nits
)
E (keV)
0
4
8
12
3020 3050 3080
keV
RTR
Theta=150Theta=15000
In=60In=6000, Out=30, Out=3000
Ion Beam Centre
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1.8MeV 4He ERD, SigmaCalc cross sections Simulation of CD2 150nm/CH2 150nm/CD2 150nm
16keV detector resolution, Bohr straggling
6μm mylar range foil
DataFurnace and SIMNRA agree at:
0.1% (yields), 400eV (edge positions)~800eV (edge widths)
Excellent agreement with MCERD
400 500 600 700 800 900 10000
2000
4000
6000Structure 2, Calculation 19
DEPTH NDF RBX RUMP SIMNRA
Yiel
d (a
rb. u
nits
)
E (keV)
Theta=30Theta=3000
In=15In=1500, Out=15, Out=150 0 (angle to surface) (angle to surface)
Ion Beam Centre
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Heavy Ion RBS
Simulation of 50nm Au/200nm SiO2/Si(3.5MeV 7Li+, Bohr straggling, 16keV detector resolution, pure Rutherford scattering, pileup, SRIM 2003)
GISA: SRIM91
RUMP, SIMNRA, DataFurnace agree at:
0.3% (Yield/Height)700eV (edge pos’ns)
SIMNRA, DataFurnaceagree at:
800eV (edge widths)
500 1000 2800 2900 3000 31000
1000
2000
9000
12000Structure 1, Calculation 9
Yie
ld (a
rb. u
nits
)
E (keV)
DEPTH GISA MCERD NDF RBX RUMP SIMNRA
Theta=150Theta=15000
In=60In=6000, Out=30, Out=3000
Ion Beam Centre
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Heavy Ion ERDSimulation of 50nm Au/200nm SiO2/Si (50MeV 127I10+, Bohr straggling, 200keV detector resolution, SRIM 2003, multiple scattering)
MCERD not known to be good
Analytical codes appear to have 20% error on scattered Isignal
Outstanding problem
Theta=40Theta=4000
10000 25000 30000 350000.0
5.0x105
1.0x106
1.5x106
2.0x106
4.0x106
6.0x106
8.0x106
127I scatteredfrom Au
Au recoilsSi recoilsfrom SiO2
Si recoilsfrom substrate
O recoilsfrom SiO2
Structure 1, Calculation 12
Yiel
d (a
rb. u
nits
)
E (keV)
DEPTH MCERD MCERD 127I from Au NDF RBX SIMNRA
In=10In=1000, Out=30, Out=300 0 (angle to surface)(angle to surface)
Ion Beam Centre
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1MeV 3He+ NRASimulation of CD2 150nm/CH2 150nm/CD2 150nm
d(3He, 4He)pd(3He, p)4He
Q=18.35MeV1980 cross-sections
6um range foil
Low energy (4He) signal hard to calculate. NDF carries calculation to lower energies
Excellent agreement for p signal
W. MW. Mööller and F. ller and F. BesenbacherBesenbacher, , NuclNucl. Instr. and Meth. . Instr. and Meth. 168 (1980) 111168 (1980) 111
Theta=170Theta=17000
In=0In=000, Out=10, Out=1000
Ion Beam Centre
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1MeV 2H+ NRASimulation of a bulk Fe4N sample
14N(d,a)12CQ=13.57MeV1mb/sr
6um range foil
Inverse kinematics below 550keV
5000 5500 6000 65000
1
2
3
4
5Structure 3, Calculation 21
Yie
ld (a
rb. u
nits
)
E (keV)
NDF SIMNRA
Theta=170Theta=17000
In=0In=000, Out=10, Out=1000
Ion Beam Centre
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Real Spectrum of a-Sia-Si, 2MeV, 3.840(8)keV/ch, 1.95(2)msr, 150.0(2)0
scattering angle, 46.0(5)uC
“… all the codes obtain excellent agreement in the important high energy region of the Si signal”
0 250 500 750 1000 12500
5000
10000
15000Real data 1: a-Si
Data DEPTH GISA NDF RUMP SIMNRA
Yiel
d (c
ount
s)
E (keV)
G. Lulli, E. Albertazzi, M. Bianconi, G.G. Bentini, R. Nipoti, RG. Lulli, E. Albertazzi, M. Bianconi, G.G. Bentini, R. Nipoti, R. Lotti, Nucl. . Lotti, Nucl. InstrumInstrum. Methods B170 (2000) 1.. Methods B170 (2000) 1.
Ion Beam Centre
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Real Spectra of Certified Implant481(3).1013/cm2 Sb implant in 90nm oxide/a-Si/c-Si
1.5MeV 4He+
1500 & 1700 detectors
Si
O
Sb
Counting statistics: Counting statistics: 0.05%0.05%
Gain uncertainty: 0.3%Gain uncertainty: 0.3%
Total experimental Total experimental uncertainty (excluding uncertainty (excluding stopping): 0.8%stopping): 0.8%
SbSb fluencefluence determined using SRIM 2003 stopping: determined using SRIM 2003 stopping: 481.15(55).10481.15(55).101313/cm/cm22 (0.1%)(0.1%)
K. H. K. H. EckerEcker, U. , U. WWäätjentjen, A. Berger, L. , A. Berger, L. PerssonPersson, W. , W. PritzcowPritzcow, M. , M. RadtkeRadtke, H. , H. RiesemeierRiesemeier, , NuclNucl. . InstrumInstrum. Methods B188 (2002) 120. Methods B188 (2002) 120
Ion Beam Centre
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HfO2/Si, 2.5MeV 4He+, 1650 scattering
SigmaCalc cross-sections for O (2*Rutherford at 2.5MeV)
Assuming HfOx result is:296(4) ×1015 Hf/cm2
599(5) ×1015 O/cm2
2.96(8) ×1015 Zr/cm2
Uncertainty consistent with counting statistics
1500 1550 16000
2000
4000
6000
8000
10000
12000
14000
1350 1400 1450 15000
20
40
60
80
100
0 500 1000 1500 20001
10
100
1000
10000
550 600 6502200
2400
2600
2800
3000
c)
Real data 3: hafnium oxide on silicon
Yie
ld (c
ount
s)
Channel
Hf
d)
Yie
ld (c
ount
s)
Channel
Zr
Yiel
d (c
ount
s)
Channel
HfO
Si
Zr
pile-upplural scattering,slit scattering,unknown
a) b)
data GISA NDF RUMP SIMNRA
O
Yiel
d (c
ount
s)
Channel
Ion Beam Centre
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Si bulk / Re 5nm/(Co 2nm/Re 0.5 nm)15
1 MeV 4He RBS, 1600scattering, 15 keV
Average layer thicknessDataFurnace:
356(30).1013Re/cm2
207(17).1014Co/cm2
SIMNRA:368(31).1013Re/cm2
227(13).1014Co/cm2
Average layer thickness difference (normalised)
28pm for the Re layers and 94pm for the Co layers
Roughness in conformal layers equivalent to features 0.6nm high and 40nm wide
N.P. Barradas, J.C. Soares, M.F. da Silva, F. PN.P. Barradas, J.C. Soares, M.F. da Silva, F. Páászti, and E. Szilszti, and E. Sziláágyi, Nucl. Instrum. Methods B 94 (1994) 266gyi, Nucl. Instrum. Methods B 94 (1994) 266 ; ; N.P. Barradas, Nucl. Instrum. N.P. Barradas, Nucl. Instrum. Methods B190 (2002) 247Methods B190 (2002) 247
0
500
1000
1500
Yie
ld (c
ount
s)
θ=45º
Yie
ld (c
ount
s)
data NDF SIMNRA
0
2000
4000
6000
θ=78º
Yield (counts)
0
10000
20000
30000θ=80º
0
1000
2000
3000
4000
θ=82º
Yield (counts)
600 700 800 9000
1000
2000
3000
4000θ=83º
E (keV)
Yie
ld (c
ount
s)
600 700 800 9000
1000
2000
3000
4000
Real data 5: Co/Re multilayer
θ=84º
Yield (counts)
E (keV)
Glancing exit geometry
Ion Beam Centre
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Conclusions (I)
• All codes perform to design• New generation codes (DataFurnace & SIMNRA)
– Simulation results usually almost indistinguishable – Excellent results for RBS, HI-RBS, ERD (also RUMP)– Excellent results for EBS– Excellent results for NRA (including inverse kinematics)– Fair results for HI-ERD (also RBX)– Roughness and double scattering approximated– Accurate pileup (good in RUMP)
• MCERD comparison– Need MC code for HI-ERD!– MC code is completely independent algorithmically– Equivalent results from MC code validates analytical codes
• Summary– All codes give reasonable results– For HI-ERD you need MCERD– For channelling you need RBX (or a Monte Carlo code)– Otherwise, for best results you need DataFurnace or SIMNRA
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Conclusions (II)
• Code validation: 0.1% agreement at best• SIMNRA and DataFurnace are usually indistinguishable• Independent implementation of same algorithms• Independent algorithms (MCERD) also agree
• Incidental demonstration that SRIM03 stopping powers are (accidentally) correct (at 0.6%) for 1.5MeV 4He on Si (best stopping powers are currently known at only 2%)
• Thanks to IAEA!
Nuclear Instruments and Methods B262 (2007) 281-303summary at: Nuclear Instruments and Methods B266 (2008) 1338-1342
http://www.mfa.kfki.hu/sigmabase/ibasoft/