Nano-Materials Characterization

Nano-Materials Characterization

Yoram Shapira, EE Nano-bio-electronics 18.12.01

Growth and

Processing

Characterization

and Analysis

Design and

Modeling

Nano

Systems


Analytical Technique

Typical Application

Signal Detected Elements

Detection Limits

Depth Resolution

Lateral Probe Size

TXRF Metal contamination

X-rays S - U 109-1012

Atoms/cm2 10 mm

RBS Thin film composition

He atoms Li - U 1 - 10 at% (Z<20) 0.01 - 1 (Z>20)

2-20 nm 2 mm

XPS Surface analysis Depth profiling

Photo- electrons

Li - U 0.01 - 1 at% 1-10 nm 10 m – 2 mm

EDAX (EDS)

elemental microanalysis

X-rays B - U 0.1 - 1 at% 1 – 5 m 1 m

Quad SIMS

Dopant profiling Surface microanalysis

Secon- dary ions

H - U 1014-1017

Atoms/cm3 <5 nm 1 m (Imaging)

30 m (D Profiling)

TOF SIMS

Surface microanalysis

Secon- dary ions

H - U 108

Atoms/cm2 <1 monolayer

0.1 m (Imaging)

Nano-Materials CharacterizationAnalyticalTechnique

TypicalApplication

Signal DetectedElements

DetectionLimits

DepthResolution

Lateral ProbeSize

AES Surface analysisand depthprofiling

Augerelectrons

Li U 0.1 - 1 at% <2 nm 100 nm

HRAES Surfaceanalysis, microarea depthprofiling

---“--- Li U 0.01 - 1 at% 2 - 6 nm <15 nm

SEM Surface imaging Secondary &backscatteredelectrons

3 nm

AFM Surface imaging Atomic forces 0.01 nm 1.5 5 nm

HRSEM High resolutionsurface imaging

Secondary &backscatteredelectrons

0.7 nm

STM Surface imaging Tunnelingcurrents

0.01 nm 0.1 nm



Typical Application

Signal Detection Limits

Depth Resolution

Lateral Probe Size

FTIR Dopants and contamination

Infrared photons

1011-1012

Atoms/cm3 1-10 mm 2 mm

PL Dopants and contamination

Photons 1011-1012

Atoms/cm3 1 - 3 m >5 m

Raman Dopants and contamination

Photons 1019

Atoms/cm3 1 m 1 m

XRD Structure and contamination

X-rays

1020

Atoms/cm3 3 mm 15 m

HEED Structure and contamination

X-rays

1020

Atoms/cm3 5 nm 0.1-10 m

ION micro- probe

Dopants and contamination

Ions

5x1017

Atoms/cm3 5 nm 0.1 mm

HRTEM [TED] [EDS]

Nano-structure [Xtal structure] [element analysis]

Electrons [Electrons]

1m-1nm

10m-0.5nm



Typical Application

Signal Depth Resolution

Probe Size

HRTEM [TED] [EDS]

Nano-structure Xtal structure Element analysis]

Electrons Electrons

1m-1nm

10m-0.5nm

Courtesy Yossi LEREAH

Transmission Electron Microscope

• Electron source: W, LaB6, FEG• Condenser Lenses (Electromagnetic)• Sample• Objective Lens (determine the point resolution)• Post Sample Lenses• Detector: electron- light converter

• Chemical analysis: EDS, GIF

Wavelength at 200KV - 0.0025nm

Bragg’s Law2dsinq=lL



Objective Lens The Core of TEM

• Back Focal Plane: Diffraction Pattern• Image Plane• Diffraction Contrast: Bright Field or Dark Field by

excluding one of the beams (in the back focal plane)• Phase Contrast by including all beams


Crystallization of Ge:Al (1)

A branched Morphology in Material Science that is relevant to Life Science

Contrast: Mass thickness, Bragg Conditions

Diffraction: Polycrystalline, Preferred orientation

•

Yossi LEREAH TEL AVIV University


Crystallization of Ge:Al (2)

• Phase Contrast reveals the periodicity of the atoms.

• The interface is rough down to atomic scale


Melting of Nano-Particles

• Melting temperature depends on the particle size.

• Existence of surface melting.

• Diffraction Contrast between solid and liquid phases







Typical Application

Signal Probe Size

SEM Surface imaging

Secondary & backscattered electrons

3 nm

HRSEM High resolution imaging

Secondary & backscattered electrons

0.8 nm

Collected signals in SEM

Sample

Incident beam

Secondary electrons (SE)

Backscattered electrons (BSE)

Cathodoluminescence(CL)

X-rays

Absorbed current

Courtesy Z. Barkay

Energy distribution of SE and BSE

Courtesy Z. Barkay

Signal emission from interaction volume

Rp

Courtesy Z. Barkay

The origin of high SE spatial resolution

• High resolution SE(1): 1 nm• Lower resolution SE(2): 0.1-1 m

Courtesy Z. Barkay

Composition dependenceE=30keV

Usually 0.1, at 30KeV=(z)

Courtesy Z. Barkay

Basic SEM modes of operation - summary

(*) usually sizes of 1cm, dependent on SEM configuration

(**) voltage and Z dependent

Additional modes: Voltage contrast (VC) and EBIC - usually used in devices and p-n junctions.

Signal/Mode Information Material Resolution

Secondary electrons (SE)

Morphology All (*) ~1nm

Backscattered electrons (BSE)

Atomic number

All (*) 0.1-0.5m(**)

X-ray (EDS or WDS)

Atomic composition

All (flat) ~1m

(CL)Cathodo- luminescence

Bandgap, impurities, lifetimes

Insulators and semi- conductors

~ 1m

Courtesy Z. Barkay

AntHuman hairEye of an ant

Courtesy A. Merson


Surface, Atomic number, Element imaging

BSE

Cu

SE

Courtesy Z. Barkay


Courtesy Z. Barkay


Courtesy Z. Barkay



Typical Application


Detection Limits

Depth Resolution

Probe Size

EDAX elemental microanalysis

X-rays B - U 0.1 - 1 at% 1 – 5 m 1 m

Atomic mapping and analysis

Cl

Brr

Agr

EDS analysis of AgClBr fiber cross section

0102030405060

0 0.2 0.4 0.6 0.8 1

fiber diameter (mm)

% a

tom

ic

BrClAg

Courtesy Z. Barkay


Courtesy CEA



Typical Application


Detection Limits

Depth Resolution

Probe Size

AES Surface analysis and depth profiling

Auger electrons

Li U 0.1 - 1 at% <2 nm 100 nm

FE-AES Surface analysis, micro area profiling

---“--- Li U 0.01 - 1 at% <2 nm <15 nm


Auger process

Courtesy A. Merson

Courtesy A. Merson

Auger Emission

a. X-ray fluorescenceb. Auger emission

Courtesy A. Merson

Courtesy PHI

Courtesy PHI


Courtesy PHI

Courtesy PHI


Courtesy PHI


Courtesy PHI


Courtesy PHI




Typical Application


Detection Limits

Depth Resolution

Probe Size

XPS Surface analysis Depth profiling

Photo- electrons

Li - U 0.01 - 1 at% 1-10 nm 10 m – 2 mm


Courtesy PHI


Courtesy PHI


Courtesy PHI


Courtesy PHI


Courtesy PHI



Typical Application


Detection Limits

Depth Resolution

Probe Size

Quad SIMS Dopant profiling Surface microanalysis

Secon- dary ions

H - U 1014-1017

Atoms/cm3 <5 nm 1 m (Imaging)

30 m (D Profiling)

TOF SIMS Surface microanalysis

Secon- dary ions

H - U 108

Atoms/cm2 <1 monolayer

0.1 m (Imaging)


Courtesy A. Merson

Uac

L

מטרהגלאי

vm

2

22L

TUzm ac=

Courtesy A. Merson


Courtesy PHI


Courtesy PHI


Courtesy A. Merson

I~exp(-2kd)

Courtesy A. Merson

Non-contact mode

Courtesy A. Merson


Courtesy Y. Rosenwaks


Materials Characterization

Courtesy Dr. Z. Barkai

Courtesy Dr. Z. Barkai


STM: Si(7x7)


A superlattice of alternating GaSb (12 ml) and InAs (14 ml) was MBE grown by W. Barvosa-Carter, B. R. Bennett, and L. J. Whitman. Only every-other lattice plane [Sb (reddish) and As (blueish)] is exposed on the (110) surface.


Iron (on Cu) “Coral”


Courtesy Z. Barkay


Courtesy Z. Barkay





Courtesy Dr. S. Richter





Thank you for your attention

Yoram [email protected]


Documents

Nano-Materials Characterization