7. advanced sem low kv imaging 14 mse-602 2013 advanced sem marco cantoni nb 0.5 mm 3sn...
TRANSCRIPT
MSE-602 2013 advanced SEM Marco Cantoni
7. advanced SEM
SEM• Low voltage SE imaging
• Condition of the surface, coatings, plasma cleaning
• Low voltage BSE imaging
• Polishing for BSE, EDX and EBSD, effect of ion beam
etching/polishing
1
MSE-602 2013 advanced SEM Marco Cantoni
100
50
10
5
10.5 1 2 5 10 20 30
FE LaB6
W
Tension d'accélération (kV)
Rés
olut
ion
(nm
)
Basse tension/haute résolution: - observation de la surface réelle - échantillons non-métallisés - faible endommagement dû au faisceau
Haute tension/haute résolution: - effets de bord - détails fins non-résolus - fort endommagement dû au faisceau
1985
2010
Field emission gun monochromatorsbeam boosters, beam deceleration,Lens-design: In-lens, Semi-in-lens, immersion lensShort working distance
Detectors:Everhard-Thornley (SE)In-column (through the lens, in-lens, “in-beam”)Low Voltage BSE detection, energy filtering (separation of materials and topography contrast)
Analytical SEM:SDD EDX detectors (high throughput, large collection angle)High-speed EBSD detectorsBeam currents of several 100 nA
Latest generation of SEM
High voltage,high resolution:• Edge effects• Charging effects• Beam damage
low voltage, high resolution:• Observation of the “real” surface• Non-metallic samples• Reduced beam damage
2
MSE-602 2013 advanced SEM Marco Cantoni
SEM low kV imaging
No specimen preparation needed:Low kV imaging of non-conducting, low density samples
FEI MagellanOperator: Ingo GestmannSamples: Marco Cantoni
Al2O3 Nano-crystals
3
MSE-602 2013 advanced SEM Marco Cantoni
SEM low kV imaging
No specimen preparation needed:Low kV imaging of non-conducting, low density samples
FEI MagellanOperator: Ingo GestmannSamples: Marco Cantoni
Carbon nano-tubes(MWCT)
4
MSE-602 2013 advanced SEM Marco Cantoni
SEM low kV imaging
No specimen preparation needed:Low kV imaging of non-conducting samples
Liquid filledorganic membranes
Zeiss Nvision 40Marco Cantoni
5
MSE-602 2013 advanced SEM Marco Cantoni
SEM low kV imaging
No specimen preparation needed:Low kV imaging of non-conducting samples
Liquid filledorganic membranes
Zeiss Nvision 40Marco Cantoni
6
MSE-602 2013 advanced SEM Marco Cantoni
SEM low kV imaging
Purely organic specimen: non-conductive, low density:Metal coating
HeLa Cells, Graham KnottMarco Cantoni, Nvision 40
15nm Ag/Pd coating
3nm Os coating3nm Os coating
7
MSE-602 2013 advanced SEM Marco Cantoni
SEM low kV imaging
“Easy” sample:
SC wireNb3Sn in Cu matrix
8
MSE-602 2013 advanced SEM Marco Cantoni
SEM low kV imaging
“Easy” samples: Everhard-Thornleydetector (SE)
Solid state BSEdetector
9
MSE-602 2013 advanced SEM Marco Cantoni
SEM low kV BSE imaging
Solid state BSEdetector
2keV, In-ColumnEsB detector
10
MSE-602 2013 advanced SEM Marco Cantoni
SEM low kV imaging “Easy” samples:
11
MSE-602 2013 advanced SEM Marco Cantoni
SEM low kV imaging “Easy” samples:
12
MSE-602 2013 advanced SEM Marco Cantoni
SEM low kV imaging “Easy” samples:
13
MSE-602 2013 advanced SEM Marco Cantoni
Contamination by hydro-carbons
• contamination “spoils” imaging at low kV
• How to avoid (at CIME):– plasma cleaning of the sample before
inserting– Plasma clean the chamber at each
insertion (multi-user environment)
XL30 FEG & EVACTRON
NVision40 & EVACTRON
SEM low kV imaging
14
MSE-602 2013 advanced SEM Marco Cantoni
0.5 mmNb3Sn multifilament superconducting cable
Nb3Sn superconductor multifilament cable:14’000 Nb3Sn filaments (diameter ~5um) in bronze matrix
SEM: Preparation for analytical EM
Solid State BSE detector20kV acceleration voltage
Mechanical polishing <-> Ar ion beam polished
EDX maps
Sn
Cu
Nb
15
MSE-602 2013 advanced SEM Marco Cantoni
Mechanical polishing:• Grains of harder phase
incorporated in softer matrix• Deformed microstructure at
surface reduces formation of Kikichi lines in EBSD
SEM BSE/EDX/EBSD
After Ar ion polishing (Gatan PIPS)
Sn
Cu
Nb
16
MSE-602 2013 advanced SEM Marco Cantoni
in-chamberET-detectorSE
in-column“InLens”SE-detector
in-column, “energy-selective” EsBBSE-detector
Ion polishing
17
MSE-602 2013 advanced SEM Marco Cantoni
Nb3Sn multifilament Superconductors
Materials & orientation contrast
SEM low kV BSE imaging
NVision 401.8kV EsB detector5µm
18
MSE-602 2013 advanced SEM Marco Cantoni
Nb3Sn multifilament Superconductors
Materials & orientation contrast
FIB/SEM low kV BSE imaging
19
MSE-602 2013 advanced SEM Marco Cantoni
Goal of final polishing:Removal of the damaged surface layermechano-chemical polishing (EBSD) or ion polishing
Interaction volumeBlue: scattered electronsRed: backscattered electrons (leaving the sample surface)
Monte-Carlo Simulation CASINO v2.42
escape depth of BSE: Nb3Sn 30kV: 800nm
5kV: 50nm
1kV: < 5nm
SEM preparation: polishing
1kV5kV
30kV
20
MSE-602 2013 advanced SEM Marco Cantoni
New HR-SEM at CIME
• Starting point: XL-30 SFEG SIRION (since 2001)• First semi-in-lens HR-SEM:
in-lens (through the lens) detection of SE and BSE
Resolution in UHR mode: 1.5 nm at 10 kV (or higher); 2.5 nm at 1 kV
21
MSE-602 2013 advanced SEM Marco Cantoni 22
MSE-602 2013 advanced SEM Marco Cantoni 23
MSE-602 2013 advanced SEM Marco Cantoni
Best “SEM” at EPFL: FIB Nvision@CIME
24
MSE-602 2013 advanced SEM Marco Cantoni
Two different contrasts with one scan: parallel detectors
25
MSE-602 2013 advanced SEM Marco Cantoni 26
MSE-602 2013 advanced SEM Marco Cantoni 27
MSE-602 2013 advanced SEM Marco Cantoni 28
MSE-602 2013 advanced SEM Marco Cantoni 29
MSE-602 2013 advanced SEM Marco Cantoni 30
MSE-602 2013 advanced SEM Marco Cantoni 31
MSE-602 2013 advanced SEM Marco Cantoni
Introducing...MERLIN™– Analytical power for the sub-nanometer world –
32
MSE-602 2013 advanced SEM Marco Cantoni
Double condenser lens Aperture independent probe current adjustment
Beam Booster Brightness of the electron probe
maintained for low landing energies
MERLIN™– Analytical power for the sub-nanometer world –
Proven GEMINI® final lens design New double condenser lens for highest
probe current possibilities (300 nA) Beam booster technology maintains
brightness of all electron probes including low landing energies
True on-axis in-lens SE and BSE detectors
► GEMINI® II designComplete detection
system
High stability field emitter cathode Maximum probe current 300 nA
Energy selective Backscatter detector (EsB)
In-lens Secondary Electron detector
GEMINI® II final lens
33
MSE-602 2013 advanced SEM Marco Cantoni 34
MSE-602 2013 advanced SEM Marco Cantoni
In-lens SE(Secondary Electrondetector)
Topographical informationwith on-axis in-lens SE detector
MERLIN™– Analytical power for the sub-nanometer world –
GEMINI® II design► Complete detection
system
Complete detection system: Unique double in-lens detection Acquisition of pure secondary and
backscatter electron signals Separation of compositional, topographical
and crystalline surface information
35
MSE-602 2013 advanced SEM Marco Cantoni
EsB(Energy selective Backscatter detector)
Energy filtering grid
Si
Si3N4
TiN
Ti
Compositional contrastwith on-axis in column EsB detector
MERLIN™– Analytical power for the sub-nanometer world –
Complete detection system: Unique double in-lens detection Acquisition of pure secondary and
backscatter electron signals Separation of compositional, topographical
and crystalline surface information
GEMINI® II design► Complete detection
system
36
MSE-602 2013 advanced SEM Marco Cantoni 37
MSE-602 2013 advanced SEM Marco Cantoni 38
MSE-602 2013 advanced SEM Marco Cantoni 39
MSE-602 2013 advanced SEM Marco Cantoni 40
MSE-602 2013 advanced SEM Marco Cantoni 41
MSE-602 2013 advanced SEM Marco Cantoni 42
MSE-602 2013 advanced SEM Marco Cantoni 43
MSE-602 2013 advanced SEM Marco Cantoni 44
MSE-602 2013 advanced SEM Marco Cantoni 45
MSE-602 2013 advanced SEM Marco Cantoni
Sapphire
46