ELEMENTAL AND ISOTOPIC ANALYSIS BY D-SECONDARY ION MASS SPECTROMETRY (D-SIMS)

Nathalie VALLE (nathalie.valle@list.lu)

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

Primary ions

>> 1015 at/cm2 (dynamic regime)< 1013 at/cm2 (static regime)

Chemical analysis

(elemental and isotopic)

Sample

Mass spectrometerSeparation by mass to charge ratio

(m/z)

Ejected particles

Secondary ions

positive ions

negative ions

Different types of measurements

1E+01

1E+02

1E+03

1E+04

1E+05

1E+06

1E+07

1E+08

1E+09

1E+10

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150

amu

inte

nsiti

es c

/s

133Cs

23Na

24Mg

40Ca

39K

27Al

63Cu65Cu

66Zn

64Zn

1H

27Al2

Monatomic ions

Polyatomic ions

Isotopes

Mass spectrum : Secondary ion intensities = f (a.m.u)

Different types of measurements

Imaging : Secondary ion intensities = f (x and y)

From ̴ (5×5)μm2 up to (800×800)μm2

C

Ce

FeHigh

Low

intensitiesLateral resolution down to 50 nm

Coll. J. Lacaze, CIRIMAT, Toulouse

Depth profiling : Secondary ion intensities = f (sputtering time)

Different types of measurements

1E+00

1E+02

1E+04

1E+06

1E+08

0 500

Se

co

nd

ary

io

n In

ten

sitie

s

[co

un

ts/s

]

Sputtering time [s]

Si

B

Raw data

1E+13

1E+14

1E+15

1E+16

1E+17

1E+18

0.0 1.0 2.0 3.0

Depth [µm]

Co

nce

ntr

ation

B [

ato

m/c

m3]

B

Depth resolution down to 1 nm

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 IMS-6f CAMECA NanoSIMS 50

Imaging

CAMECA SC-Ultra

Depth profiling

37 instruments worldwide

Advanced semiconductors,

materials science

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

III-V compounds analysis

Examples of detection limits in silicon.

Element Bombardment Detection limit

(ppm)

Impact energy

(keV)

B O2+ 0.1 0.5

0.001 10

As Cs+ 0.1 0.5

0.04 13

Imaging: detection limit

1µm

Martensite

FerriteBainite

Austenite

SEM micrograph, SE mode: typical

microstructure of a multiphase steel

(J. Drillet, ArcelorMittal)

1 Valle et al., Appl. Surf. Science 252 (2006) 7051-7053;

2 C.P. Scott and J. Drillet, Scripta Materialia, 56 (2007) 489-492

Techniques Spatial resolution Detection limit

NanoSIMS 1 50 nm < 0.006 wt%

EELS 2 40nm 0.04 wt %

Bainitic ferrite

Martensite

NanoSIMS image - (30×30)mm2

The carbon concentration of bainitic ferrite is below the

detection limit of the Electron Energy Loss Spectroscopy

(EELS):

%C bainitic ferrite < 0.04%wt

C

2.3µm

SIMS quantification

01

2

3

45

6

7

8

9Study 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

N. Tsavdaris et al. Materials Science Forum, 2015.

Coll. D. Chaussende, LMGP, Grenoble

RSF (CN/Si)

Relative Sensitivity Factor

Implanted standard sample: N, 180keV, 9.5×1012 cm-2

0,00E+00

5,00E-04

1,00E-03

1,50E-03

2,00E-03

2,50E-03

3,00E-03

3,50E-03

4,00E-03

0 1 2 3 4 5 6 7 8 9

Inte

nsi

tés

CN

no

rma

lisé

es

(c/

s)

Numéro de la bande de dopage

#SiC-4

germe

Bande non dopéeUndoped stripe

StripeNorm

aliz

ed

CN

-in

ten

sitie

s

Depth profiling: quantification at high depth resolution

C

Si

N

H

Cr

0 2 4 6

Depth, nm

1e20

1e21

1e22

1e23

Co

nc, a

tom

/cm

3

Cr/ epitaxial graphene / SiC

Impact energy: 150 eV

Graphene layer: ~ 1 nm

N doping < 1 at. %

H ~ 15-17 at. %

A. Merkulov et al., Poster @ SIMS Europe 2014, Münster

Michalowski et al. Appl. Phys. Lett. 109, 011904 (2016)

W. Strupinski et al. Nano Lett. 2011, 11, 1786–1791.

Characterisation of graphene

.

Elemental mapping at high lateral resolution

• TiO2 NPs in skin cells

Presence of nanoparticles in TiO2

sun cream…

Overlay CN & TiO

Nucleus

CN

10 µm 10 µm

TiO

Cytoplasm

Presence of Ti in cytoplasm only

Detection of nanoparticles in skin cells

V. Lopes et al., J. Nanobiotechnol (2016) 14:22

Quantification of light elements

600

Heat treatment

T2: fast cooling

0 3 10 30

T1

1µm

High

Low

intensities

0s 30s 600s

γ γ

B precipitates

B solid solution

B segregation

at dislocation

Development of high strength B-added steels for automotive industry The addition of B (~ 20 ppm) increases the hardenability of steels.

0

2

4

6

8

10

12

14

16

18

20

1 2 3 4 5 6

Co

nce

ntr

atio

n B

(p

pm

)

Time (s)

Solid solution

0 3 10 30 120 600

Ongoing G. Da Rosa ‘s thesis (J. Drillet, K. Hoummada, N. Valle, P. Maugis, V. Hebert)

Isotopic measurements

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…

SIMS capability to measure the different isotopes of one element

2. Relevant in geochemistry and cosmochemistry

For what purpose : e.g: to determine the origin of water in the Solar System

δ18O , δ17O …

3. Relevant in material sciences

For what purpose: e.g: to study transport phenomena,

corrosion, diffusion…

Oxygen

16O

99.759%

18O

0.204%

17O

0.037%

Oxygen

18O

49.963%

16O

50%

17O

0.037%

Natural

abundance

Artificial

enrichment

https://en.wikipedia.org/wiki/Esquel_(meteorite)

Isotopic measurements

An innovative methodology to study glass alteration mechanisms and kinetics (coll. A. Verney-Carron, M. Saheb)

Pallo

t-F

rossard

(2006)

Troyes Cathedral (XIIIth c.)

tDe

2 DH2O

e: alteration thickness (m)

D : diffusion coefficient (m²/s)

t: time of exposure (s)

Altered layer

Medieval stained

glass

18O/16O

0.002

0.005

× 2.5

Drizzle

Isotopic measurements: O and H

Fissure 1Fissure 2

Fissure 3

Origin of cracks ?

Study of the propagation of cracks in Ni-based alloys during stress corrosion cracking

Field of view: (50 x 50) mm2

High

intensities

Low

intensities

P. Laghoutaris’s thesis (CEA)

U-bend test

18O/16O

CrO

D/H

Analysed

area

18O, 2D

3D imaging

16O

Red Oxygen

Green Carbon

Presence of

submicron domain

structures

Analyzed area : (20 x 20) mm2, sputtering rate: 1nm/s

Characterisation of thin films of immiscible polymer systems

PS + PMMA

O

Audinot et al.: Applied Surface Science,

2004, Surf. Interface Anal., 2005Si

PS

Si substrate

Depth profiling in small area 1/2

http://www.gecco.tu-bs.de/pubs.html

http://www.compoundsemiconductor.net/article/95856-whats-the-best-business-model-for-nanowire-leds.html

3D GaN pillars

High

Low

intensities

50 µm

Dopant

Ga

GaN microrods

Depth profiling in small area 2/2

High

Low

intensities 12 µm

Ga

Depth profile in

small area

No

rma

lized

in

ten

sit

ies

Depth (arbitrary unit)

Dopant

Ga

Dopant

Co

nc

ne

ntr

ati

on

of

do

pan

t (u

.a)

Depth (arbitrary unit)

Determination of

different dopant

concentrations

(calibration with a

standard sample)