Transcript Talk I (XPS, Ultra High Vacuum Technology)

‫محمد‬
‫رسول هللا صلى هللا‬
‫عليه وسلم‬
X-ray Photoelectron
Spectroscopy (XPS)
Master IMAPC:
Responsible: Prof.Danielle Raiser
Training Supervisor:
Dr. Spiros Zafaieratos
By:Driss SOUBANE
Wednesday, 08 April
2015
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1
This work was achieved in :
•
École Européenne de Chimie, Polymères et Matériaux de Strasbourg (ECPM) -
Laboratoire des Matériaux, Surfaces et Procédés pour la Catalyse (LMSPC)-CNRS
Wednesday, 08 April
2015
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Outline
Training
report
.pdf
i. Motivations
ii. Principles of the technique XPS
iii. Instrumentations
Pumps-UHV
XPS Machine
v. Results and discussions
vi. Conclusions and perspective
vii. Appendices
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2015
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MOTIVATIONS
Thin film coating, Semiconductor,
Electronics, Computer
Automotive, Battery, Catalyst,
Glass
Why the technique XPS?
-Non destructive
-Qualitative and quantitative technique
-Ability to explore the first few atomic
layers 1-10 nm
Magnetic memory, Laser,
Lighting, cosmetic
Paper and wood, Plating,
Polymer and plastic, Printing,
Ceramic, Chemical
And so on…
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2015
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Principles
I. Motivations
Principle of the technique XPS
II. Principles
V
III.Instrumentations
Auger electron
V
- Pumps for UHV
- XPS equipment
VI. Results and
Discussions
Photoelectron
Ekin = hυ - Eb
Vac
Ф
V. Conclusions and
EF
Perspectives
X-ray
M
L2,3 ou 2p
Fluorescence X Or
Auger emission
+
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2015
L1 ou 2s
K ou 1s
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Principles
I. Motivations
II. Principles
III.Instrumentations
Relative probabilities of relaxation by emission of X-ray photon
and by Auger electron emission [1]
- Pumps for UHV
- XPS machine
VI. Results and
Discussions
V. Conclusions and
Perspectives
Obviously, the two phenomena could take place and compete. However,
according to figure 2 the possibility of relaxation by X-ray fluorescence is
favored over that of Auger emission for heavy elements.
[1] D. Briggs and M.P. Seah, “Practical Surface analysis (second edition) Vol. 1: Auger and X-ray photoelectron spectroscopy, John
Wiley & sons Ltd 1990
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2015
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Ultra High Vacuum pumps
I. Motivations
II. Principles
III.Istrumentations
To attain UHV in reasonable time, outgazing of the chamber
walls must be performed by increasing the temperature of the
entire spectrometer to the range of 150-200°C for several
hours (this procedure is called bake-out or baking)
- Pumps for UHV
- XPS machine
VI. Results and
Discussions
V. Conclusions and
Perspectives
Wednesday, 08 April
2015
-mechanical pumps Edwards RV5 rotary vane pump and
grundfos pump type JP5WYAA
-turbomolecular pumps Turb-V 250 Macro Torr
-ion pump VacIon type 911503A
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Ultra High Vacuum pumps
I. Motivations
II. Principles
III.Istrumentations
- Pumpsfor UHV
- XPS machine
VI. Results and
Discussions
V. Conclusions and
Perspectives
-turbomolecular pumps Turb-V 250 Macro Torr
-ion pump VacIon type 911503A
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2015
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VG Microtech LTD XPS( the old machine) LMSPC
I. Motivations
II. Principles
III.Istrumentations
- Pumpsfor UHV
- XPS machine
VI. Results and
Discussions
V. Conclusions and
Perspectives
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2015
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Thermo VG Scientific T 190 (the new machine) LMSPC
I. Motivations
II. Principles
III.Istrumentations
- Pumpsfor UHV
- XPS machine
VI. Results and
Discussions
V. Conclusions and
Perspectives
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2015
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optimum takeoff angle
I. Motivations
95% of the signal intensity is derived from a depth three times the
attenuation length of the emerging electron with the solid.
II. Principles
III.Istrumentations
I ( z)  I z 0 expd / 
d  3
I / I  5%
0
I  I O / I  95%
- Pumpsfor UHV
- XPS machine
Emerged electrons
VI. Results and
Discussions
V. Conclusions and
Perspectives
α
dd
λ
So the optimum takeoff angle is 90° which gives theoretically
the ideal relative position of the specimen analyzer.
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2015
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Optimization of the channeltron voltage/VG Microtech LTD
I. Motivations
Specimen: monocrystal Ni (111)
II. Principles
-It is clear that the percentage signal/noise reveals more enhancements when
the channeltron potential increases
III.Istrumentations
- Pumpsfor UHV
- XPS machine
VI. Results and
Discussions
-3100 V is choosen as an optimal voltage
-We have disqualified 3300 V for the two reasons the former is that the
spectrum corresponding to 3300 V shows many spikes and the latter is that
practical lower potentials are preferred to preserve equipment from any
possible damage
V. Conclusions and
Perspectives
In fact, the channeltron potential makes part of electronic system ensuring amplification of the
signal, so hypothetically greater is this potential more intense are the peaks
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2015
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Impacts of changing pass energy value/VG Microtech LTD
I. Motivations
Specimen: monocrystal Ni (111)
II. Principles
Pass energy value of 20 eV was privileged
III.Istrumentations
- XPS machine
VI. Results and
Discussions
V. Conclusions and
Perspectives
Intensity(a.u)
- Pumpsfor UHV
4
1.2x10
E2eV
E5eV
E10eV
E20eV
E50eV
E100eV
4
1.0x10
3
8.0x10
3
6.0x10
3
4.0x10
3
2.0x10
0.0
800
820
840
860
Binding energy (eV)
880
Theoretically, high resolution of spectra is consistent with low energy pass value. In effect, pass energy
is a way to filter electron emerging to the detector by their kinetic energy thus lower is the pass energy,
narrower are the range of electron energy detected through the analyzer
Wednesday, 08 April
2015
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Horizontal specimen holder position impact/VG Microtech LTD
I. Motivations
Specimen: monocrystal Ni (111)
II. Principles
III.Istrumentations
- XPS machine
VI. Results and
Discussions
V. Conclusions and
Perspectives
Intensity (a.u)
- Pumpsfor UHV
7.0x10
4
6.5x10
4
6.0x10
4
5.5x10
4
5.0x10
4
4.5x10
4
4.0x10
4
3.5x10
4
3.0x10
4
2.5x10
4
2.0x10
4
1.5x10
4
1.0x10
4
5.0x10
3
X8
X10
X12
X13
X13.5
X14
X16
X17
X18
X18.5
X19
X19.5
840
850
860
870
Binding Energy (ev)
from 8 mm position to 16 mm we obtain well defined peak with high intensity
beyond 13.5 the peaks get less fine and broader
we figure out that 13 mm is the optimal position
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2015
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Quantitative analysis/Thermo VG Scientific T 190
I. Motivations
II. Principles
III.Istrumentations
powder of silver/copper 100 nm ( Nominal bulk
composition 2% Cu)
- Pumpsfor UHV
- XPS machine
VI. Results and
Discussions
V. Conclusions and
Perspectives
The sample was treated at 300°C in 1 bar hydrogen atmosphere for an hour
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[Background
subtraction
]
D.A.
Shirley,
Phys.
Rev.
B
5,
4709-4714
(1972).
2015
Quantitative analysis/Thermo VG Scientific T 190
I.
Motivations
II.
Généralités
the surface of this alloy is composed of 6.67% of copper and
93.33% of silver.
X Ag
X Cu
III. Techniques
expérimentales
VI. Résultats Et
Discussion
-Film Absorbeur
CISe-CIGSeCIGSeS-CIS
-Film Buffer CdS
-Fenêtre optique
ZnO
V. Conclusions Et
Perspectives
Comparison of surface with “bulk” composition indicates that there is an
important surface segregation of Cu on the samples.
Wednesday, 08 April
2015
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 14.2
Conclusions
I.
Motivations
II.
Généralités
Through this work we have first reveal
III. Techniques
expérimentales
VI.
Résultats
Discussion
Et
-Film
Absorbeur
CISe-CIGSeCIGSeS-CIS
-Film Buffer CdS
-Fenêtre
ZnO
optique
•ability of the technique XPS to probe the first atomic layers, identify
elements accomplish quantitative analysis
•analyzed two different samples the monocrystal Ni (111) and the powder of
copper-silver (2%Cu) using two different XPS machines VG Microtech and
thermo VG scientific T 190
V. Conclusions Et
Perspectives
•Survey along with narrower scan were performed to find out the optimal
value of channeltron potential, optimal horizontal sample position , pass
energy value.
•At the end of this work we have come back to calculate the atomic fraction
ratio composing the powder and we revealed that the surface is rich of
silver about 93% and 6 %
Wednesday, 08 April
2015
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Perspective
‫محمد‬
‫رسول هللا صلى هللا‬
‫عليه وسلم‬
Thanks.
•Carrying on this work will be of great interest especially to test the impact
of changing the nature of the X-ray source by using Mg Kα instead of Al Kα
used or both of them. Another way is also to analyze the sample samples
by means of AES
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2015
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Appendices (Source Dr. Spiros courses)
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2015
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Appendices (Source Dr. Spiros courses)
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2015
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Appendices
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2015
(Source Dr. Spiros courses)
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Appendices
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2015
(Source Dr. Spiros courses)
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Appendices
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2015
(Source Dr. Spiros courses)
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Appendices
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2015
(Source Dr. Spiros courses)
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Appendices
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2015
(Source Dr. Spiros courses)
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Survey and narrower scan/VG Microtech LTD
I. Motivations
Specimen: monocrystal Ni (111)
II. Principles
III.Istrumentations
- Pumpsfor UHV
- XPS machine
VI. Results and
Discussions
V. Conclusions and
Perspectives
-The identification of the peaks reveals the presence of the nickel (2p1/2 2p3/2, 3p3/2, 3p3/2 and 2s)
-One can also notice the presence of other peaks related to Auger electron emission viz. L3M45M45
and L3M23M45 confirming also the presence of nickel within the analyzed sample
Wednesday, 08 April
2015
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Introduction
I. Motivations
II. Principles
III.Instrumentations
developed in the 1960s by a research group of Prof.
K. Siegbahn (Noble prize in physics 1981) at
Uppsala University, Sweden
- Pumps for UHV
- XPS machine
VI. Results and
Discussions
V. Conclusions and
Perspectives
Traditionally known as Electron Spectroscopy for
Chemical Analysis (ESCA) :
-X-ray
Photoelectron
Spectroscopy
-Ultraviolet Photoelectron Spectroscopy
Wednesday, 08 April
2015
(XPS)
(UPS)
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Conclusions
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2015
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