Tem

Materials Characterization Labwww.mri.psu.edu/mcl

Transmission Electron Microscopy (TEM)& Scanning Transmission

Electron Microscopy (STEM)Joe Kulik

194 MRI [email protected]/814-865-0344

15 June 2005


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


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:


Outline

― Overview of TEM/STEM―MCL capabilities― Examples of applications from PSU investigations― How to get started ― Campus resources― a brief lab tour


Incident high-kVelectron beam

ThinSample

Direct beam

CharacteristicX-rays Visible

light

BremsstrahlungX-rays

Elasticallyscatteredelectrons

Inelasticallyscatteredelectrons

Backscatteredelectrons

Augerelectrons

Secondaryelectrons

‘Absorbed’electrons

Electron-holepairs


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


DiffractionMode

FinalDiffraction

Pattern

Diffraction pattern from ordered perovskite structure


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


ThinSample

Incident high-kVelectron beam

CharacteristicX-rays

Electron-holepairs

p i nReversed biased p-i-n junction

X-ray Energy Dispersive Spectroscopy

t

VOutput


EDS Example


Electron Energy Loss Spectroscopy (EELS)Final microscopelens

Electron prismspectrometer Quadrupole

magnifiersDetector

Lossspectrum

Expandedspectrum


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


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


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


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.


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


Co-existence of the modulated and ordered structures• Some BaTiO3 grains in


100 nm

100 nm

G.Y. Yang et al.


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.


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



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



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


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



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



Identification of Au particles on Ge nanowires.E-beam probe size is < 1 nm.

Trammell, Kulik, Dickey

Growth of Ge nanowires


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


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


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.


Twinning Superlattice of InP

[111]

5 nm

J. Wang et al.


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


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)


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.


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)


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/)


www.mri.psu.edu/mcl

Joe Kulik194 MRI [email protected]

Tem

Business

Transcript of Tem