Post on 02-Jun-2015
Materials Characterization Labwww.mri.psu.edu/mcl
Transmission Electron Microscopy (TEM)& Scanning Transmission
Electron Microscopy (STEM)Joe Kulik
194 MRI Buildingjuk12@psu.edu/814-865-0344
15 June 2005
Materials Characterization Labwww.mri.psu.edu/mcl
250 MRLAugust 179:45 AMParticle Characterization
114 MRI BldgAugust 249:45 AMX-ray photoelectron spectroscopy (XPS/ESCA)
114 MRI BldgAugust 2411:00 AMAuger Electron Spectroscopy (AES)
541 Deike Bldg.July 279:45 AMChemical analysis (ICP, ICP-MS)
541 Deike Bldg.August 109:45 AMSmall angle x-ray scattering (SAXS)
114 MRI Bldg August 39:45 AMAtomic Force Microscopy (AFM)
250 MRL Bldg.July 209:45 AMOrientation imaging microscopy (OIM/EBSD)
114 MRI BldgJuly 1311:00 AMTEM sample preparation
114 MRI BldgJuly 139:45 AMFocused Ion Beam (FIB)
250 MRL Bldg.July 610:15 AMHigh temperature sintering lab (20 min lecture only)
250 MRL bldg.July 69:45 AMDielectric Characterization (25 min lecture only)
250 MRL Bldg.June 299:45 AMX-ray Diffraction (XRD)
541 Deike Bldg.June 2211:00 AMAnalytical SEM
541 Deike Bldg.June 229:45 AMScanning electron microscopy (SEM)
114 MRI BldgJune 159:45 AMTransmission Electron Microscopy (TEM/STEM)
250 MRL Bldg.June 89:45 AMThermal analysis (TGA, DTA, DSC)
LocationDateTimeTechnique
NOTE LOCATIONS: The MRI Bldg is in the Innovation Park near the Penn Stater Hotel; MRL Bldg. is on Hastings Road.More information: www.mri.psu.edu/mcl
Summer Characterization Open HousesSummer Characterization Open Houses
Materials Characterization Labwww.mri.psu.edu/mcl
BeaverStadium
Park Ave.
Park Ave.
Porter RoadPollock Road
University Drive
College Ave.
ShortlidgeR
oad North
Bur ro w
esR
oa d
00
00
00
00
00
00
00
00
00
Centre Community
Hospital
E&ES Bldg:SEM
Hosler Bldg:SEM, ESEM, FE-SEM, EPMA, ICP, ICP-MS,BET, SAXS
MRI Bldg:XPS/ESCA, SIMS, TEM, HR-TEM, FE-Auger, AFM, XRD
Atherton Street
(322 Business)
MRL Bldg:SEM, XRD, OIM, DTA, DSC, TGA, FTIR, Raman, AFM, Powder, dielectric, prep, shop, IC, UV-Vis
Hastings Road
Penn StaterHotel
00
Materials Characterization Lab LocationsBldg TelephoneMRL 863-7844MRI 865-0337Hosler 865-1981E&ES 863-4225
Route 322
I-99 00
Steidle Bldg:Nanoindenter
Deike Bldg:
Materials Characterization Labwww.mri.psu.edu/mcl
Outline
― Overview of TEM/STEM―MCL capabilities― Examples of applications from PSU investigations― How to get started ― Campus resources― a brief lab tour
Materials Characterization Labwww.mri.psu.edu/mcl
Incident high-kVelectron beam
ThinSample
Direct beam
CharacteristicX-rays Visible
light
BremsstrahlungX-rays
Elasticallyscatteredelectrons
Inelasticallyscatteredelectrons
Backscatteredelectrons
Augerelectrons
Secondaryelectrons
‘Absorbed’electrons
Electron-holepairs
Materials Characterization Labwww.mri.psu.edu/mcl
Electron Gun
Condenser 1
Condenser 2
Objective
IntermediateLens
ProjectorLens
Specimen
ObjectiveAperture
Final Image
2nd Image
Image Mode
(Conventional) TEM
1st Image
Diffraction contrast from dislocatios
High resolution of twins in InPnanowires
Materials Characterization Labwww.mri.psu.edu/mcl
DiffractionMode
FinalDiffraction
Pattern
Diffraction pattern from ordered perovskite structure
Materials Characterization Labwww.mri.psu.edu/mcl
Condenser/ObjectiveField Region
Front Focal Plane
Back Focal Plane (BFP)
Specimen
ScanCoils
Scanning TEM (STEM)
Imaging of BFP to detector plane
Bright fielddetector
Dark fielddetector
Materials Characterization Labwww.mri.psu.edu/mcl
ThinSample
Incident high-kVelectron beam
CharacteristicX-rays
Electron-holepairs
p i nReversed biased p-i-n junction
X-ray Energy Dispersive Spectroscopy
t
VOutput
Materials Characterization Labwww.mri.psu.edu/mcl
Electron Energy Loss Spectroscopy (EELS)Final microscopelens
Electron prismspectrometer Quadrupole
magnifiersDetector
Lossspectrum
Expandedspectrum
Materials Characterization Labwww.mri.psu.edu/mcl
Tungsten cathodeAccelerating voltage: 120 keVPoint-to-point resolution: 0.34 nm Objective Lens- Spherical aberration coef: 3.0 mm- Specimen tilt range: ±60° Energy dispersive x-ray spectroscopy (EDS)
10 mm2 detector area 140 eV resolution Spatial resolution: 5 nm
Specimen HoldersSingle tilt Double tilt Heating Tmax = 900°C (single tilt) Cooling LN2 (double tilt)
Philips EM420T
Materials Characterization Labwww.mri.psu.edu/mcl
LaB6 CathodeAccelerating voltage: 200 keVUltra high resolution pole piece (0.5 mm Cs) Point-to-point resolution: 0.20 nm Gatan TV rate camera Specimen HoldersJEOL single tilt Gatan double tilt Stage tilt: +/-10°
Energy dispersive x-ray spectroscopy (EDS)
30 mm2 detector area 140 eV resolution Spatial resolution: <2 nm
JEOL JEM-2010
Materials Characterization Labwww.mri.psu.edu/mcl
Field emission gunUltra high res pole piece (0.5 mm Cs) 1.9 Å point-to-point resolution Bright-field/dark-field STEM CCD cameraEnergy-Dispersive X-ray SpectroscopyEDAX Detector 138 eV resolution at MnKa30 mm2 detector area Electron Energy Loss Spectroscopy (EELS) with 0.7 eV resolution Specimen HoldersJEOL Single tilt low background holder Gatan Analytical holder with Be specimen cup Gatan Tilt-rotation holder with Be specimen cup Gatan Double tilt liquid nitrogen holder
JEOL JEM-2010F
Materials Characterization Labwww.mri.psu.edu/mcl
Examples from PSU Research• BaTiO3 Dielectrics for capacitors, G.Y. Yang et al.• Shallow Ohmic Contacts to p-InAs for Heterojunction Bipolar
Transistors, E. Lysczek, S. Wang J. Robinson, & S. Mohney• Au-Catalyzed Growth of Ge nanowires, T. Trammell, J. Kulik, & E.
Dickey• Niobium Oxide Characterization with EELS, M. Olszta & E.
Dickey• GaN Film on Composition-Graded AlGaN Buffer on Si, X. Weng &
E. Dickey• Spectral Imaging of Si Nanowires, J. Wang et al.• Twinning Superlattice in InP Nanowires, J. Wang et al.
Materials Characterization Labwww.mri.psu.edu/mcl
Microstructure of BaTiO3 Dielectric
Conventional Perovskite Structure:• as-produced BME capacitors• Partial BaTiO3 grains in
the degraded BME capacitors
111
010
101
[101]
Perovskite framework+ modulation:• Most BaTiO3 grains in
the degraded BME capacitors
Co-existence of the modulated and ordered structures• Some BaTiO3 grains in
the degraded BME capacitors
100 nm
100 nm
G.Y. Yang et al.
Materials Characterization Labwww.mri.psu.edu/mcl
High-resolution TEM images of BaTiO3in the degraded Ni-BaTiO3 MLCCs
Modulated structure Long range ordered structure
111
2 nm
010
111101
2 nm
(111)
Microstructure of BaTiO3 DielectricG.Y. Yang et al.
Materials Characterization Labwww.mri.psu.edu/mcl
Energy-Loss (eV)
460 480 500 520 540 560
a. PME-as-produced MLC*
b. BME-as-produced MLC
c. BME-degraded regular
d. BME-degraded modulated
e. BME-degraded ordered
Ti L2,3
O KA B C D
BaTiO3.00
BaTiO2.93
BaTiO2.86
BaTiO2.60
BaTiO2.60
Relative chemical shift between the dielectric grains on different structural states indicating Ti reduction
Microstructure of BaTiO3 DielectricG.Y. Yang et al.
Materials Characterization Labwww.mri.psu.edu/mcl
HRTEM images, structural model, and simulated image of long-range ordering structure of
BaTiO3 in the Degraded Ni-BaTiO3 MLCCs
7 Å
000
111
1/31/31/3
2/32/
32/3
(a)
7 Å
000
111⅔⅔⅔⅓⅓⅓
Superlattice: Ba(Ti4+
1/3Ti3+2/3)O2.67
[0001]h // [111]pBa2+
Ti 3+
Ti4+TiTi
O 2-
Partially vacated O2-
site
7 Å
Microstructure of BaTiO3 DielectricG.Y. Yang et al.
Materials Characterization Labwww.mri.psu.edu/mcl
Pd/W/Au (3/50/145nm)
Au
W
Pd-As, Voids
InAs
Buffer layer
In
Aged 250°C 9h• Reaction Depth = 6 ± 2 nm
• Some small voids present
• Indium out-diffusion
• Shallow and uniform reaction
Lysczek, Wang, Robinson, Mohney
Materials Characterization Labwww.mri.psu.edu/mcl
Pd/Pt/Au (3/50/145nm)
Au
PtVoids
Pt-In-As
Buffer layer
Aged 250°C 9h• Reacted into buffer layer
• Uniform void formation at interface
Lysczek, Wang, Robinson, Mohney
Materials Characterization Labwww.mri.psu.edu/mcl
Pt/W/Au (3/50/145nm)
Au
W
Pt-Au-In-AsInAs
Buffer LayerBuffer Layer and Au
Aged 250°C 9h• Reaction Depth = 36 ± 7nm in areas without Au penetration• Tungsten diffusion barrier failed to keep Au out in one spot
Lysczek, Wang, Robinson, Mohney
Materials Characterization Labwww.mri.psu.edu/mcl
Identification of Au particles on Ge nanowires.E-beam probe size is < 1 nm.
Trammell, Kulik, Dickey
Growth of Ge nanowires
Materials Characterization Labwww.mri.psu.edu/mcl
6500
21500
36500
51500
530.00 540.54 551.08 561.62
Energy Loss (eV)
Phot
odio
de C
ount
s (a
.u.)
NbO
Nb2O5
NbO2A
BA
A
B
D
C
E
D
C
E
CC
D C
ount
s (a
rb. u
nits
)
Niobium Oxide Characterization with EELSM. Olszta, E. Dickey
Materials Characterization Labwww.mri.psu.edu/mcl
200 nm
GaN Film on Si via Composition-Graded AlGaN Buffer
The composition-graded AlGaN buffer layer significantly reduces the threading dislocation density in the GaN film
AlGaN
GaN
Si
0002 Two-Beam Bright-Field Image
X. Weng, E. Dickey, J. Redwing
Materials Characterization Labwww.mri.psu.edu/mcl
50 nm 1 2
Energy Loss (eV)14012010080
Si+SiOxSiOx
SiOx L3 map
Si L3 map
O K map
Energy Loss (eV)550500
Si+SiOxSiOx
Energy Loss (eV)
500400300200100
Si L2,3
SiOx L2,3
O K edge
Electron energy loss spectral image of a Si nanowireJ. Wang et al.
Materials Characterization Labwww.mri.psu.edu/mcl
Twinning Superlattice of InP
[111]
5 nm
J. Wang et al.
Materials Characterization Labwww.mri.psu.edu/mcl
How to get started
• Contact me (Joe Kulik) to discuss your needs• Attend training session
– Sessions are by appointment– Informal– Typically 2 trainees per session
• Provide budget and fund number!• TEM can be time consuming for beginners
– If time is an issue, find a collaborator– There are many users at PSU
Materials Characterization Labwww.mri.psu.edu/mcl
Sample preparationMaterial must be thin (< 100 nm)High resolution requires thickness ~20 nmPreparation methods:
– Metals can be electropolished– Semiconductors and ceramics can be mechanically
thinned followed by ion thinning to achieve electron transparency
– Very fine grained powders, nanowires, nanoparticles can be dispersed on a support film (e.g., lacey carbon)
– Focused Ion Beam thinning is also an option• MCL has a dual-platform FIB (FIB/SEM)
Materials Characterization Labwww.mri.psu.edu/mcl
TEM FeesInstrument time:
Philips EM420T: $30/hrJEOL JEM-2010: $35/hrJEOL JEM-2010F: $50/hr
Staff time: $30/hrTraining fee: $300 (Includes ~16 hours of instrument time with ~ 4 to 8 hours of personalized instruction as necessary)Consultation time to discuss your samples, data, etc is free.
Materials Characterization Labwww.mri.psu.edu/mcl
Campus resources- coursework
1. Materials Science 531, Transmission electron microscopy, 3-credits:Overview of TEM, STEM and applications (Spring only)
2. Transmission electron microscopy, 1-credit lab course:Simple alignment of electron optical column, basic experiments in electron
diffraction and imaging (Consult Course Schedule)
Materials Characterization Labwww.mri.psu.edu/mcl
Campus resources- people
1. MCL (Joe Kulik, Jinguo Wang)2. Elizabeth Dickey, Associate Professor of Materials Science & Engineering3. Peter Heaney, Associate Professor of Geosciences4. Arthur Motta, Professor of Nuclear Engineering5. Theresa Mayer, Associate Professor of Electrical Engineering6. Clive Randall, Professor of Materials Science & Engineering7. Mary Beth Williams, Assistant Professor of Chemistry8. Suzanne Mohney, Professor of Materials Science & Engineering
Other resources:• www.mri.psu.edu/mcl/techniques/tem.asp (links, applications, etc)• MRI links to publications and abstract (Web of Science) searching
(www.mri.psu.edu/linkspubs/)• Microscopy Society of America (MSA) (http://www.microscopy.org/)