ELEMENTAL AND ISOTOPIC
ANALYSIS BY D-SECONDARY ION
MASS SPECTROMETRY (D-SIMS)
Nathalie VALLE ([email protected])
Brahime EL ADIB – Esther LENTZEN
Outline
1. D-SIMS: an overview
 Principle of the technique
 Types of measurements
 Facilities available at LIST
2. Main characteristics of the technique through a selection of
examples
Principle of the technique
Mass spectrometer
Separation by mass to charge ratio
(m/z)
Chemical analysis
(elemental and isotopic)
Primary ions
>> 1015 at/cm2 (dynamic regime)
< 1013 at/cm2 (static regime)
Ejected particles
Secondary ions
positive ions
negative ions
Sample
Different types of measurements
 Mass spectrum : Secondary ion intensities = f (a.m.u)
133Cs
1E+10
1E+09
1E+08
intensities c/s
1E+07
27Al
23Na
1E+06
1H
1E+05
39K
 Monatomic ions
 Polyatomic ions
 Isotopes
64Zn
63Cu
27Al
65Cu
2
40Ca
24Mg
66Zn
1E+04
1E+03
1E+02
1E+01
0
10
20
30
40
50
60
70
80
amu
90
100
110
120
130
140
150
Different types of measurements
 Imaging
High
: Secondary ion intensities = f (x and y)
C
Fe
Low
intensities
Lateral resolution down to 50 nm
Ce
From ̴ (5×5)μm2 up to (800×800)μm2
Coll. J. Lacaze, CIRIMAT, Toulouse
Different types of measurements
 Depth profiling : Secondary ion intensities = f (sputtering time)
1E+18
Secondary ion Intensities
[counts/s]
Si
Raw data
1E+06
B
1E+04
1E+02
1E+00
Concentration B [atom/cm3]
1E+08
1E+17
1E+16
B
1E+15
1E+14
1E+13
0
500
0.0
Sputtering time [s]
Depth resolution down to 1 nm
1.0
Depth [µm]
2.0
3.0
Characteristics of the D-SIMS technique

SIMS is a destructive technique.

Analysis of any vacuum compatible material including non-conductive samples.

Ease of sample preparation (exception in life sciences).

Elemental analysis:
Analysis of the full periodic table including hydrogen.
High sensitivity: typical detection limits from ppm down to ppb.

Isotopic measurements:
Precision/reproducibility (better than 5 per mil).

Depth profiling:
Depth distribution can be recorded over nanometer depth, up to tens of microns depth.
Optimized depth resolution  1nm.

2D-3D imaging:
Optimized lateral resolution  50 nm.

Quantitative analysis possible with standard samples.
Direct semi-quantification is possible in many cases using MCs+ clusters
(M = element of interest).
Different D-SIMS instruments @ LIST
CAMECA SC-Ultra
CAMECA IMS-6f
CAMECA NanoSIMS 50
Depth profiling


37 instruments worldwide
Advanced semiconductors,
materials science
Imaging


40 instruments worldwide
Materials, geology, planetary and
life sciences
Depth profiling: detection limit

Detection of trace elements and quantification of dopants with high depth resolution in semi-conductors
Element
Bombardment
B
O2+
As
Cs+
Detection limit
(ppm)
Impact energy
(keV)
0.1
0.001
0.1
0.04
0.5
10
0.5
13
Examples of detection limits in silicon.
III-V compounds analysis
Imaging: detection limit

Bainite
Austenite
Ferrite
The carbon concentration of bainitic ferrite is below the
detection limit of the Electron Energy Loss Spectroscopy
(EELS):
%C
Martensite
bainitic ferrite
< 0.04%wt
C
1µm
Bainitic ferrite
SEM micrograph, SE mode: typical
microstructure of a multiphase steel
(J. Drillet, ArcelorMittal)
Martensite
Techniques
NanoSIMS 1
EELS 2
Spatial resolution
50 nm
40nm
Detection limit
< 0.006 wt%
2.3µm
0.04 wt %
NanoSIMS image - (30×30)mm2
1
Valle et al., Appl. Surf. Science 252 (2006) 7051-7053;
2 C.P.
Scott and J. Drillet, Scripta Materialia, 56 (2007) 489-492
SIMS quantification
8
7
6
5
4
3
2
1
0
Study of nitrogen (n-type dopant) incorporation during SiC growth by
physical vapour transport
 Electron affinity: N (0 eV) / CN- (3.86 eV)  analysis of nitrogen as CN Quantification possible by using implanted standard sample (RSF) – Normalisation to Si
9
Normalized
CN- intensities
Intensités CN normalisées (c/s)
4,00E-03
#SiC-4
3,50E-03
3,00E-03
2,50E-03
2,00E-03
RSF (CN/Si)
Undoped
Bande nonstripe
dopée
1,50E-03
germe
1,00E-03
0
5,00E-04
1
2
3
4
5
6
7
8
9
Stripe
Numéro de la bande de dopage
0,00E+00
Relative Sensitivity Factor
N. Tsavdaris et al. Materials Science Forum, 2015.
Coll. D. Chaussende, LMGP, Grenoble
Implanted standard sample: N, 180keV, 9.5×1012 cm-2
Depth profiling: quantification at high depth resolution
Characterisation of graphene
Cr/ epitaxial graphene / SiC
C
Cr
1e23
Conc, atom/cm3

H
Si
W. Strupinski et al. Nano Lett. 2011, 11, 1786–1791.
1e22
Impact energy: 150 eV
N



1e21
Graphene layer: ~ 1 nm
N doping < 1 at. %
H ~ 15-17 at. %
1e20
0
2
4
Depth, nm
6
A. Merkulov et al., Poster @ SIMS Europe 2014, Münster
Michalowski et al. Appl. Phys. Lett. 109, 011904 (2016)
Elemental mapping at high lateral resolution

Detection of nanoparticles in skin cells
• TiO2 NPs in skin cells
Presence of nanoparticles in TiO2
sun cream…
CN
TiO
Nucleus
10 µm
Cytoplasm
Presence of Ti in
cytoplasm only
Overlay CN & TiO
.
V. Lopes et al., J. Nanobiotechnol (2016) 14:22
10 µm
Quantification of light elements
 Development of high strength B-added steels for automotive industry
The addition of B (~ 20 ppm) increases the hardenability of steels.
B segregation
at dislocation
γ γ
B precipitates
B solid solution
High
0s
30s
Concentration B (ppm)
20
18
16
Solid solution
14
12
10
8
6
4
2
0
1
0
600s
23
3
4
10
30
Time (s)
5
120
6
600
Heat treatment
T1
T2: fast cooling
0
Low
intensities
3
10 30
600
1µm
Ongoing G. Da Rosa ‘s thesis (J. Drillet, K. Hoummada, N. Valle, P. Maugis, V. Hebert)
Isotopic measurements

SIMS capability to measure the different isotopes of one element
1. Relevant in nuclear science
For what purpose: e.g for the identification of fission products, international control of fissile
isotope uranium-235 enrichment by IAEA…
2. Relevant in geochemistry and cosmochemistry
For what purpose : e.g: to determine the origin of water in the Solar System
δ18O , δ17O …
https://en.wikipedia.org/wiki/Esquel_(meteorite)
3. Relevant in material sciences
18O
For what purpose: e.g: to study transport phenomena,
corrosion, diffusion…
Oxygen
Oxygen
0.204%
17O
17O
0.037%
0.037%
16O
99.759%
Natural
abundance
18O
49.963%
16O
50%
Artificial
enrichment
Isotopic measurements
An innovative methodology to study glass alteration mechanisms and kinetics (coll. A. Verney-Carron, M. Saheb)
Pallot-Frossard (2006)

Troyes Cathedral (XIIIth c.)
Drizzle
0.005
18O/16O ×
2.5
Altered layer
Medieval stained
glass
0.002
e2
D t

 DH2O
e: alteration thickness (m)
D : diffusion coefficient (m²/s)
t: time of exposure (s)
Isotopic measurements: O and H

Study of the propagation of cracks in Ni-based alloys during stress corrosion cracking
High
intensities
U-bend test
18O, 2D
Analysed
area
CrO
Origin of cracks ?
Fissure 3
Fissure 2
Fissure 1
18O/16O
Low
intensities
D/H
Field of view: (50 x 50) mm2
P. Laghoutaris’s thesis (CEA)
3D imaging

Characterisation of thin films of immiscible polymer systems
PS
+
PMMA
O
16O
Presence of
submicron domain
structures
Analyzed area : (20 x 20) mm2, sputtering rate: 1nm/s
Red Oxygen
Green Carbon
PS
Si substrate
Si
Audinot et al.: Applied Surface Science,
2004, Surf. Interface Anal., 2005
Depth profiling in small area 1/2

GaN microrods
Dopant
High
Ga
Low
intensities
50 µm
3D GaN pillars
http://www.compoundsemiconductor.net/article/95856-whats-the-best-business-model-for-nanowire-leds.html
http://www.gecco.tu-bs.de/pubs.html
Depth profile in
small area
High
Ga
Normalized intensities
Depth profiling in small area 2/2
Ga
Dopant
Low
intensities
12 µm
Determination of
different dopant
concentrations
(calibration with a
standard sample)
Concnentration of dopant
(u.a)
Depth (arbitrary unit)
Dopant
Depth (arbitrary unit)