fn1_2f_spectroscopy.ppt 1523KB Jun 23 2011 10:31:50 AM

Spectroscopy

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Spectroscopy
Outputs

Inputs

e-

γ

A+

e

-

γ

Sample

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A+

Electrons Out
Auger electrons

Probe:
Electrons

Secondary electron
imaging
Backscattered
electron imaging

Transmitted
electrons

Electrons In

e-

e-

Electron diffraction

γ

Photons out
Energy Dispersive
Spectroscopy
Wavelength
Dispersive
Spectroscopy

Sample
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Probe: Photons
Photons Out
Photons In
Infrared
Visible
Ultraviolet
X-Rays

γ

Fourier Transform Infrared
Spectroscopy
Raman
Visible
Ultraviolet

X-Ray Fluorescence
X-Ray Diffraction

γ

Electrons Out
XPS, X-ray
Photoelectron
Spectroscopy

e-

Sample
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Probe: Ions
Ions Out
SIMS, Secondary

Ion Mass
Spectrometry

Ions In

A

+

A+

ToF SIMS, Time of
Flight SIMS,
ICP MS, Inductively
Coupled Plasma
Mass Spectrometry

Sample
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X-Ray Tools


X-Ray Spectroscopy
 Energy

Dispersive X-ray Spectroscopy (EDS)
 Wavelength Dispersive X-ray Spectroscopy
(WDS)

X-ray fluorescence (XRF)
 X-ray photoelectron spectroscopy (XPS)
 X-Ray Diffraction


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Energy Dispersive X-Ray
Spectroscopy, EDS
Element maps
 Spectra
 Applications
 System overview
 System image
 X-Ray detector


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EDS Applications








Used to determine the elemental composition of a
sample.
Can perform both qualitative (What is it?) and
quantitative (How much?) analysis.
Depending on the window low atomic number
elements may not be visible.
Super ultra thin windows detect down to berilium.
Older detectors may only detect fluorine and
higher.
Window less detectors are available.
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FNI 1C

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FNI 1C

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EDS Element Map

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EDS Image

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Energy Dispersive X-Ray Detector
System

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Solid state Si Li X-Ray Detector

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Example of Electron Transitions

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Vendors


EDAX

http://www.edax.com/index.html



Princeton Gamma Tech
http://www.pgt.com/



Noran/Kevex/Thermo
http://www.thermo.com/BURedirect/welcomeMsg/1,5107,28,00.html



Oxford Instruments
http://www.oxinst.com/
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Wavelength Dispersive X-Ray
Spectroscopy, WDS
System Overview
 Detector
 Image


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WDS System

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WDS
Detector
P10 gas is 90% argon and 10% methane

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Image of WDS Detector

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Wavelength Dispersive X-Ray
Spectroscopy
System Overview
 Detector
 Image


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Other X-Ray Analysis
X-Ray Photoelectron Spectroscopy (XPS)
 X-Ray Tomography Nano CT
 XRD X-Ray Diffraction


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X-Ray Photoelectron Spectroscopy
An incoming X-Ray removes a core electron
which will have a characteristic energy
based on the difference between the initial
X-Ray energy, which is of known energy,
and the energy to remove the inner electron
from the atom, which is characteristic.
 This has very high sensitivity.


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Links







http://hyperphysics.phy-astr.gsu.edu/hbase/quantum/hyd
azi.html#c3
http://elchem.kaist.ac.kr/vt/chem-ed/analytic/ac-meths.h
tm
http://elchem.kaist.ac.kr/vt/chem-ed/scidex.htm
http://www.nanopicoftheday.org/
http://www.nanopicoftheday.org/
http://
www.physics.berkeley.edu/research/crommie/index.html

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Quantum Numbers

Number

Name

Permitted Values

Defines

n

Principal

(1, 2, 3, …)

Electron shell
(1=K, 2=L, 3=M
…)

l

Azimuthal

0 to n-1

Electron cloud
shape

m

Magnetic

-l to +l

Electron shell
orientation in a
magnetic field

s

Spin

±½

Electron spin
direction

j

Inner precession

l±½
But j≠-½

Total angular
momentum

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Electron Shells
K

LI

LII

LIII

MI

MII

MIII MIV MV

n

1

2

2

2

3

3

3

3

3

l

0

0

1

1

0

1

1

2

2

s

+½ +½ -½

+½ +½ -½

+½ -½

j

½

1½ ½

1½ 1½ 2½

½

½

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½

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+½

Electron Transitions
1.
2.
3.

The change in n must be ≥ 1 (Δn ≠ 0)
The change in l can only be ±1
The change in j can only be ±1 or 0

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Other Surface Analysis Methods


Focused ion beam (FIB)



Mass spectrometry/Residual gas analyzer (Mass spec/RGA)
Secondary ion mass spectrometry (SIMS)
Time of Flight SIMS (ToF SIMS)
Atom probe microscopy









Auger electron spectroscopy (Auger or AES)
Rutherford Backscattering Spectroscopy (RBS)
Fourier transform infrared spectroscopy (FTIR)
Raman spectroscopy
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Mass Spectrometry, Mass Spec
 Residual

Gas Analyzer, RGA
 Sorts atoms, molecules and molecule
fragments based on mass.





http://elchem.kaist.ac.kr/vt/chem-ed/ms/ms-intro.htm
http://elchem.kaist.ac.kr/vt/chem-ed/ms/mag-sect.htm
http://elchem.kaist.ac.kr/vt/chem-ed/ms/quadrupo.htm
http://elchem.kaist.ac.kr/vt/chem-ed/ms/tof.htm

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Secondary Ion Mass Spectrometry




http://www.eaglabs.com/cai/simstheo/caistheo.htm
http://www.eaglabs.com/cai/simstheo/ionsput.htm
http://www.eaglabs.com/tutorial.htm

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SIMS

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ToF SIMS


ToF SIMS



http://www.phi.com/genf.asp_Q_ID_E_283

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Atom Probe Microscopes


http://www.ornl.gov/info/ornlreview/rev28-4/text/atoms.htm



Imago Scientific Instruments
http://www.imago.com/imago/

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Imago 3D Atom Probe Microscope

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Imago LEAP

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Auger Electron Spectroscopy AES


http://www.eaglabs.com/cai/augtheo/process.htm



AES has a number of advantages over X-Ray
analysis.
 It

can be confined confined to a very small spot.
 Signals are generated only from a very shallow depth into
the sample (3 nm).
 It can be combined with an ion mill to create a very detailed
analysis of bulk materials.
 Intermediate in price between SEM/EDS and more
expensive systems.
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Rutherford Backscattering
Spectroscopy, RBS


http://www.eaglabs.com/cai/rbstheo/intro.htm



Uses alpha particles (He++) to analyze a
material.

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Fourier Transform Infrared
Spectroscopy FTIR

Uses Infra-Red EM radiation to analyze
molecules, especially organic compounds.

Bending, stretching, rotation
Infrared light of different energies
is passed through the sample.
How the sample absorbs light is
analyzed.
•http://www.forumsci.co.il/HPLC/FTIR_page.html
•http://mmrc.caltech.edu/FTIR/FTIRintro.pdf
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Raman Spectroscopy
A change in polarizability of the
molecule results in a shift in
frequency of a laser.

http://carbon.cudenver.edu/public/chemistry/classes/chem4538/raman.htm
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Focused Ion Beam FIB
This method uses a beam of ions and magnetic
lenses to focus the ions onto the sample.
 FIB is used to drill tiny holes in a sample.
 This is usually used to see the cross sectional
structure of the device.






http://dsa.dimes.tudelft.nl/usage/technology/FIB/
http://mfgshop.sandia.gov/1400_ext_IonBeam.htm
http://www.nanopicoftheday.org/2003Pics/FIBNanofab.htm

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Example of FIB

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FIB Preparation for TEM

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FIB Links



http://www.ipr.umd.edu/ionbeam/ast-fib.html
http://cmm.mrl.uiuc.edu/techniques/fib.htm

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Links





http://hyperphysics.phy-astr.gsu.edu/hbase/quantum/hydazi.html#c3
http://elchem.kaist.ac.kr/vt/chem-ed/analytic/ac-meths.htm
http://elchem.kaist.ac.kr/vt/chem-ed/scidex.htm
http://www.nanopicoftheday.org/

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Other Surface Analysis Methods


Focused ion beam (FIB)



Mass spectrometry/Residual gas analyzer (Mass spec/RGA)
Secondary ion mass spectrometry (SIMS)
Time of Flight SIMS (ToF SIMS)
Atom probe microscopy









Auger electron spectroscopy (Auger or AES)
Rutherford Backscattering Spectroscopy (RBS)
Fourier transform infrared spectroscopy (FTIR)
Raman spectroscopy
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