Electro Scan Electro Scan Environmental Scanning Electron - - PowerPoint PPT Presentation

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Electro Scan Electro Scan Environmental Scanning Electron - - PowerPoint PPT Presentation

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Electro Scan Electro Scan Electro Scan Electro Scan Environmental Scanning Electron Environmental Scanning Electron Microscopes Microscopes 1 1 Seeing Things Youve Never Seeing Things Youve Never Seen Before Seen Before Electro

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SLIDE 1

1 1

Electro ElectroScan Scan

Electro ElectroScan Scan

Environmental Scanning Electron Environmental Scanning Electron Microscopes Microscopes

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SLIDE 2

2 2

Electro ElectroScan Scan

Seeing Things You’ve Never Seeing Things You’ve Never Seen Before Seen Before

Uncoated Silicon Nitride Uncoated Silicon Nitride Dissolving Table Salt Dissolving Table Salt Living Aphid Living Aphid Oxidizing Iron 800º C Oxidizing Iron 800º C Crystallizing KCL 600º C Crystallizing KCL 600º C Oil and Water Droplets Oil and Water Droplets

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SLIDE 3

3 3

Electro ElectroScan Scan

ESEM - Environmental SEM ESEM - Environmental SEM

I I Investigate samples in a variety of

Investigate samples in a variety of environments manipulating pressure, environments manipulating pressure, temperature, humidity, and composition of temperature, humidity, and composition of ambient gas or liquid. ambient gas or liquid.

I I Observe non-conductive, wet, dirty,

Observe non-conductive, wet, dirty,

  • utgassing, dynamic samples without
  • utgassing, dynamic samples without

cleaning or coating. cleaning or coating.

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SLIDE 4

4 4

Electro ElectroScan Scan

Scanning Electron Microscope Scanning Electron Microscope (SEM) (SEM)

Mechanical Pump High Vacuum Pump Electron Source Wehnelt Anode Condenser Lenses Objective Aperture Scan Coils Objective Lens Sample Display CRT Magnification Control Detector Scan Signals Image Signal Sample Chamber Gun Chamber Mechanical Pump High Vacuum Pump Electron Source Wehnelt Anode Condenser Lenses Objective Aperture Scan Coils Objective Lens Sample Display CRT Magnification Control Detector Scan Signals Image Signal Sample Chamber Gun Chamber Mechanical Pump High Vacuum Pump Electron Source Wehnelt Anode Condenser Lenses Objective Aperture Scan Coils Objective Lens Sample Display CRT Magnification Control Detector Scan Signals Image Signal Sample Chamber Gun Chamber

An SEM forms an image by scanning a finely An SEM forms an image by scanning a finely focused beam of electrons over the sample surface. focused beam of electrons over the sample surface.

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SLIDE 5

5 5

Electro ElectroScan Scan

SEM Signal Generation SEM Signal Generation

Cathodoluminescence (light) Auger electrons Backscattered electrons Characteristic X-rays Bremsstrahlung Secondary electrons Primary beam Heat Elastically scattered electrons Transmitted electrons Specimen current X-rays Cathodoluminescence (light) Auger electrons Backscattered electrons Characteristic X-rays Bremsstrahlung Secondary electrons Primary beam Heat Elastically scattered electrons Transmitted electrons Specimen current X-rays Cathodoluminescence (light) Auger electrons Backscattered electrons Characteristic X-rays Bremsstrahlung Secondary electrons Primary beam Heat Elastically scattered electrons Transmitted electrons Specimen current X-rays

The beam electrons generate a variety of signals as they interact with sample atoms. The beam electrons generate a variety of signals as they interact with sample atoms.

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SLIDE 6

6 6

Electro ElectroScan Scan

SEM Electron Optics SEM Electron Optics

Electron Source (Crossover) Condenser Lens Objective Lens Aperture Image of Source Sample Image of Source Divergence Increased Excluded by Aperture (further demagnified) (demagnified) Divergence

Chromatic Aberration Spherical Aberration

Minimum Spot Size Slower electrons focus closer to lens wider angles Electrons at focus closer to lens

Column Optics Lens Aberrations

Electron Source (Crossover) Condenser Lens Objective Lens Aperture Image of Source Sample Image of Source Divergence Increased Excluded by Aperture (further demagnified) (demagnified) Divergence

Chromatic Aberration Spherical Aberration

Minimum Spot Size Slower electrons focus closer to lens wider angles Electrons at focus closer to lens

Column Optics Lens Aberrations

Electron Source (Crossover) Condenser Lens Objective Lens Aperture Image of Source Sample Image of Source Divergence Increased Excluded by Aperture (further demagnified) (demagnified) Divergence

Chromatic Aberration Spherical Aberration

Minimum Spot Size Slower electrons focus closer to lens wider angles Electrons at focus closer to lens

Column Optics Lens Aberrations

The electron optics of the column are designed to demagnify the image of the electron The electron optics of the column are designed to demagnify the image of the electron source, forming the smallest possible spot on the sample surface. source, forming the smallest possible spot on the sample surface. Lens aberrations limit the demagnification. Lens aberrations limit the demagnification.

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SLIDE 7

7 7

Electro ElectroScan Scan

SEM Resolution SEM Resolution

Convergence Angle Spot Diameter Convergence Angle Spot Diameter Convergence Angle Spot Diameter

SEM resolution is ultimately limited by the diameter of the spot SEM resolution is ultimately limited by the diameter of the spot formed by the beam on the sample surface. formed by the beam on the sample surface.

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SLIDE 8

8 8

Electro ElectroScan Scan

Volume of Interaction Volume of Interaction

backscattered electrons Source of Source of Source of electron-excited characteristic X-rays Primary electron beam Sample secondary electrons backscattered electrons Source of Source of Source of electron-excited characteristic X-rays Primary electron beam Sample secondary electrons backscattered electrons Source of Source of Source of electron-excited characteristic X-rays Primary electron beam Sample secondary electrons

Beam electrons generate signals throughout a region Beam electrons generate signals throughout a region known as the Volume of Interaction known as the Volume of Interaction

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SLIDE 9

9 9

Electro ElectroScan Scan

Resolution and Contrast Resolution and Contrast

B B S S E E S S E E

Gold on Carbon Gold on Carbon Toner Toner Tungsten Carbide Tungsten Carbide

Resolution is dependent on sample type as well as signal type. Resolution is dependent on sample type as well as signal type.

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SLIDE 10

10 10

Electro ElectroScan Scan

Depth of Field Depth of Field

Electron Beam Plane of Best Sample surface Region in Effective Focus Focus Depth of Field Electron Beam Plane of Best Sample surface Region in Effective Focus Focus Depth of Field Electron Beam Plane of Best Sample surface Region in Effective Focus Focus Depth of Field

The small convergence angle of the beam in an SEM yields excellent depth of field. The small convergence angle of the beam in an SEM yields excellent depth of field.

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SLIDE 11

11 11

Electro ElectroScan Scan

Characteristic X-rays Characteristic X-rays

Inner Shell Electron Primary Electron Outer Shell Electron X-ray Photon M Line Lines L K Lines α β α α β γ Inner Shell Electron Primary Electron Outer Shell Electron X-ray Photon M Line Lines L K Lines α β α α β γ Inner Shell Electron Primary Electron Outer Shell Electron X-ray Photon M Line Lines L K Lines α β α α β γ

The energy of a characteristic X-ray is determined by The energy of a characteristic X-ray is determined by the atomic structure of the emitting element. the atomic structure of the emitting element.

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12 12

Electro ElectroScan Scan

X-ray Spectrum X-ray Spectrum

An X-ray spectrum shows the intensity of X-ray emissions An X-ray spectrum shows the intensity of X-ray emissions from various elements present in the sample. from various elements present in the sample.

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SLIDE 13

13 13

Electro ElectroScan Scan

X-ray Maps X-ray Maps

X-ray maps can show the spatial distribution of elements in the sample. X-ray maps can show the spatial distribution of elements in the sample.

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SLIDE 14

14 14

Electro ElectroScan Scan

Electron Gun Electron Gun

Wehnelt Cathode voltage (e.g. -30 kV) Wehnelt voltage (e.g -30.5 kV) Anode (0 V) Electron "crossover" electrons Filament Wehnelt Cathode voltage (e.g. -30 kV) Wehnelt voltage (e.g -30.5 kV) Anode (0 V) Electron "crossover" electrons Filament Wehnelt Cathode voltage (e.g. -30 kV) Wehnelt voltage (e.g -30.5 kV) Anode (0 V) Electron "crossover" electrons Filament

The high voltages used in an electron gun require a high vacuum. The high voltages used in an electron gun require a high vacuum.

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SLIDE 15

15 15

Electro ElectroScan Scan

Everhart-Thornley Detector Everhart-Thornley Detector

Electron Beam Collector grid Scintillator Light guide Photo-multiplier Secondary electrons (+300 V) (+12 kV) Secondary Electron Signal Out Electron Beam Collector grid Scintillator Light guide Photo-multiplier Secondary electrons (+300 V) (+12 kV) Secondary Electron Signal Out Electron Beam Collector grid Scintillator Light guide Photo-multiplier Secondary electrons (+300 V) (+12 kV) Secondary Electron Signal Out

The high voltages used in a conventional secondary electron detector The high voltages used in a conventional secondary electron detector require a high vacuum in the sample chamber. require a high vacuum in the sample chamber.

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SLIDE 16

16 16

Electro ElectroScan Scan

Charging Artifacts Charging Artifacts

Nonuniform Charge Balance Nonuniform Charge Balance at 1.7 kV at 1.7 kV Typical Charging Artifacts Typical Charging Artifacts at 20 kV at 20 kV

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SLIDE 17

17 17

Electro ElectroScan Scan

CSEM Vacuum System CSEM Vacuum System

Sample Chamber Gun Chamber High Vacuum Pump Mechanical Pump 10 Torr

  • 5

Sample Chamber Gun Chamber High Vacuum Pump Mechanical Pump 10 Torr

  • 5

Sample Chamber Gun Chamber High Vacuum Pump Mechanical Pump 10 Torr

  • 5

In a CSEM the column and sample chamber share In a CSEM the column and sample chamber share the same high vacuum environment the same high vacuum environment

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SLIDE 18

18 18

Electro ElectroScan Scan

ESEM Vacuum System ESEM Vacuum System

Manual Valve

G4 G1 G2 V2 V5 G3 V4 V3 V13 G5 V7 V8

Regulator Valve

V10 V9 V11

Auxiliary Gas Vent

V6 G7 Dif 1 Dif 2 RP1 RP2 RP3 V1 V12

Vent Water Vapor

Gauge Valve

Ion Pump

Sample Chamber 10 Torr EC1 10 Torr

  • 1

EC2 10 Torr

  • 4

Column 10 Torr

  • 5

Gun Chamber 10 Torr

  • 7

Manual Valve

G4 G1 G2 V2 V5 G3 V4 V3 V13 G5 V7 V8

Regulator Valve

V10 V9 V11

Auxiliary Gas Vent

V6 G7 Dif 1 Dif 2 RP1 RP2 RP3 V1 V12

Vent Water Vapor

Gauge Valve

Ion Pump

Sample Chamber 10 Torr EC1 10 Torr

  • 1

EC2 10 Torr

  • 4

Column 10 Torr

  • 5

Gun Chamber 10 Torr

  • 7

Manual Valve

G4 G1 G2 V2 V5 G3 V4 V3 V13 G5 V7 V8

Regulator Valve

V10 V9 V11

Auxiliary Gas Vent

V6 G7 Dif 1 Dif 2 RP1 RP2 RP3 V1 V12

Vent Water Vapor

Gauge Valve

Ion Pump

Sample Chamber 10 Torr EC1 10 Torr

  • 1

EC2 10 Torr

  • 4

Column 10 Torr

  • 5

Gun Chamber 10 Torr

  • 7

In the ESEM Multiple Pressure Limiting Apertures separate In the ESEM Multiple Pressure Limiting Apertures separate the column vacuum from the sample environment. the column vacuum from the sample environment.

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SLIDE 19

19 19

Electro ElectroScan Scan

Multiple Pressure Limiting Multiple Pressure Limiting Apertures Apertures

PLA 1 PLA 2

10 Torr 10 Torr

  • 1

10 Torr

  • 4

10 Torr

  • 5

PLA 1 PLA 2

10 Torr 10 Torr

  • 1

10 Torr

  • 4

10 Torr

  • 5

PLA 1 PLA 2

10 Torr 10 Torr

  • 1

10 Torr

  • 4

10 Torr

  • 5

Multiple PLAs permit larger aperture diameters and shorter gas path lengths. Multiple PLAs permit larger aperture diameters and shorter gas path lengths.

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20 20

Electro ElectroScan Scan

Electron Scattering Electron Scattering

Minimal Scattering Scatter < 5% m < 0.05 Partial Scattering 5% to 95% Scatter m from = 0.05 to 3.0 Complete Scattering Scatter >95% m > 3.0 Minimal Scattering Scatter < 5% m < 0.05 Partial Scattering 5% to 95% Scatter m from = 0.05 to 3.0 Complete Scattering Scatter >95% m > 3.0 Minimal Scattering Scatter < 5% m < 0.05 Partial Scattering 5% to 95% Scatter m from = 0.05 to 3.0 Complete Scattering Scatter >95% m > 3.0

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Electro ElectroScan Scan

Poisson Distributions Poisson Distributions

Average Number of Scattering Events = 0.05

10 20 30 40 50 60 70 80 90 100 1 2 3 4 5 6 7 8 9 10

Number of Scattering Events % Probability

Average Number of Scattering Events = 0.7

10 20 30 40 50 60 70 80 90 100 1 2 3 4 5 6 7 8 9 10

Number of Scattering Events % Probability

Average Number of Scattering Events = 3

10 20 30 40 50 60 70 80 90 100 1 2 3 4 5 6 7 8 9 10

Number of Scattering Events % Probability

Average Number of Scattering Events = 0.05

10 20 30 40 50 60 70 80 90 100 1 2 3 4 5 6 7 8 9 10

Number of Scattering Events % Probability

Average Number of Scattering Events = 0.7

10 20 30 40 50 60 70 80 90 100 1 2 3 4 5 6 7 8 9 10

Number of Scattering Events % Probability

Average Number of Scattering Events = 3

10 20 30 40 50 60 70 80 90 100 1 2 3 4 5 6 7 8 9 10

Number of Scattering Events % Probability

Average Number of Scattering Events = 0.05

10 20 30 40 50 60 70 80 90 100 1 2 3 4 5 6 7 8 9 10

Number of Scattering Events % Probability

Average Number of Scattering Events = 0.7

10 20 30 40 50 60 70 80 90 100 1 2 3 4 5 6 7 8 9 10

Number of Scattering Events % Probability

Average Number of Scattering Events = 3

10 20 30 40 50 60 70 80 90 100 1 2 3 4 5 6 7 8 9 10

Number of Scattering Events % Probability

Even when the average number of scattering events is relatively high, Even when the average number of scattering events is relatively high, some fraction of electrons reach the sample without being scattered at all some fraction of electrons reach the sample without being scattered at all

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Electro ElectroScan Scan

Beam Profiles Beam Profiles

Minimal Scattering Regime Partial Scattering Regime Complete Scattering Regime Minimal Scattering Regime Partial Scattering Regime Complete Scattering Regime Minimal Scattering Regime Partial Scattering Regime Complete Scattering Regime

In the partial scattering regime, unscattered electrons remain focused In the partial scattering regime, unscattered electrons remain focused within the original spot on the sample surface. within the original spot on the sample surface.

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SLIDE 23

23 23

Electro ElectroScan Scan

Resolution in Gas Environment Resolution in Gas Environment

Environmental Environmental High Vacuum High Vacuum A gaseous environment does not necessarily degrade image resolution. A gaseous environment does not necessarily degrade image resolution.

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SLIDE 24

24 24

Electro ElectroScan Scan

Imaging Current Scattering Loss Imaging Current Scattering Loss

Beam Loss due to gas dispersion (at 20kV)

1% 10% 100% 5 10 15 20 25 30

Path length from Pressure Limiting Aperture to the sample (mm) Useful Imaging Beam Current

50%

10 Torr 5 Torr 2 Torr 1 Torr 0.5 Torr 0.2 Torr

Beam Loss due to gas dispersion (at 20kV)

1% 10% 100% 5 10 15 20 25 30

Path length from Pressure Limiting Aperture to the sample (mm) Useful Imaging Beam Current

50%

10 Torr 5 Torr 2 Torr 1 Torr 0.5 Torr 0.2 Torr

Beam Loss due to gas dispersion (at 20kV)

1% 10% 100% 5 10 15 20 25 30

Path length from Pressure Limiting Aperture to the sample (mm) Useful Imaging Beam Current

50%

10 Torr 5 Torr 2 Torr 1 Torr 0.5 Torr 0.2 Torr

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25 25

Electro ElectroScan Scan

Environmental Secondary Environmental Secondary Electron Detector Electron Detector

V + V

  • ut

A

Gas Molecules Positive Ions Electrons

V + V

  • ut

A

Gas Molecules Positive Ions Electrons

V + V

  • ut

A

Gas Molecules Positive Ions Electrons

The ESD uses the gas in the environment to amplify the secondary electron signal The ESD uses the gas in the environment to amplify the secondary electron signal

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Electro ElectroScan Scan

Gaseous Secondary Electron Gaseous Secondary Electron Detector Detector

BSE Type III SE SE Objective Lens Insulator High Voltage Collection Electrode PLA1

ESD

Gas Tight Seal SE BSE Type III SE BSE Suppressor Electrode Suppressor Electrode Detector Ring

GSED

SE

SE BSE Type III SE SE Objective Lens Insulator High Voltage Collection Electrode PLA1

ESD

Gas Tight Seal SE BSE Type III SE BSE Suppressor Electrode Suppressor Electrode Detector Ring

GSED

SE

SE BSE Type III SE SE Objective Lens Insulator High Voltage Collection Electrode PLA1

ESD

Gas Tight Seal SE BSE Type III SE BSE Suppressor Electrode Suppressor Electrode Detector Ring

GSED

SE

SE

The GSED offers improved discrimination against BSEs and parasitic SEs The GSED offers improved discrimination against BSEs and parasitic SEs

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SLIDE 27

27 27

Electro ElectroScan Scan

Gaseous Secondary Electron Gaseous Secondary Electron Detector Detector

ESD GSED

The improved signal discrimination of the GSED enhances image quality. The improved signal discrimination of the GSED enhances image quality.

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28 28

Electro ElectroScan Scan

ESEM Charge Suppression ESEM Charge Suppression

CSEM ESEM

Gas ions, generated by the ESD and the beam, suppress charging artifacts. Gas ions, generated by the ESD and the beam, suppress charging artifacts.

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SLIDE 29

29 29

Electro ElectroScan Scan

X-ray Detection in the ESEM X-ray Detection in the ESEM

X-rays BSE BSE SE 15mm 10mm 5mm 20mm BGPL 30

  • 10 Torr
  • 1

X-rays BSE BSE SE 15mm 10mm 5mm 20mm BGPL 30

  • 10 Torr
  • 1

X-rays BSE BSE SE 15mm 10mm 5mm 20mm BGPL 30

  • 10 Torr
  • 1

A special version of the ESD permits efficient X-ray collection A special version of the ESD permits efficient X-ray collection while preserving a short beam gas path length. while preserving a short beam gas path length.

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SLIDE 30

30 30

Electro ElectroScan Scan

X-ray Analysis in the ESEM X-ray Analysis in the ESEM

20 kV 20 kV 1 kV 1 kV Accelerating Voltage Accelerating Voltage

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SLIDE 31

31 31

Electro ElectroScan Scan

Imaging Capability Imaging Capability

ESEM ESEM 5.0 Torr 5.0 Torr FE Gun FE Gun 15 kV 15 kV GSED GSED ESEM ESEM 4.9 Torr 4.9 Torr LaB6 Gun LaB6 Gun 20 kV 20 kV GSED GSED CSEM CSEM Hi Vac Hi Vac FE Gun FE Gun 2 kV 2 kV ETD ETD LV-CSEM LV-CSEM 1.4 Torr 1.4 Torr LaB6 Gun LaB6 Gun 20 kV 20 kV BSED BSED

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SLIDE 32

32 32

Electro ElectroScan Scan

Operating Pressures Operating Pressures

Vacuum in Torr

10 to 10

  • 7
  • 4

0.1 1 10 100 4.6 Torr (minimum for liquid water) 50 0.2 0.5 2 5 20

Secondary and Backscattered Electron Imaging

(1 Torr = 133 Pascal = 1.33 mBar)

Backscattered Imaging Only

ESEM LV-CSEM CSEM

SE and BSE SE and BSE SE and BSE

Vacuum in Torr

10 to 10

  • 7
  • 4

0.1 1 10 100 4.6 Torr (minimum for liquid water) 50 0.2 0.5 2 5 20

Secondary and Backscattered Electron Imaging

(1 Torr = 133 Pascal = 1.33 mBar)

Backscattered Imaging Only

ESEM LV-CSEM CSEM

SE and BSE SE and BSE SE and BSE

Vacuum in Torr

10 to 10

  • 7
  • 4

0.1 1 10 100 4.6 Torr (minimum for liquid water) 50 0.2 0.5 2 5 20

Secondary and Backscattered Electron Imaging

(1 Torr = 133 Pascal = 1.33 mBar)

Backscattered Imaging Only

ESEM LV-CSEM CSEM

SE and BSE SE and BSE SE and BSE

Only the ESEM offers secondary imaging in a low vacuum environment. Only the ESEM offers secondary imaging in a low vacuum environment. Only the ESEM permits chamber pressures sufficient to maintain wet samples. Only the ESEM permits chamber pressures sufficient to maintain wet samples.

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SLIDE 33

33 33

Electro ElectroScan Scan

LV-CSEM Vacuum System LV-CSEM Vacuum System

Sample Chamber Gun Chamber High Vacuum Pump Mechanical Pump 1 Torr Gas Flow Regulator Valve

1 Torr 10 Torr

  • 5

PLA Single Sample Chamber Gun Chamber High Vacuum Pump Mechanical Pump 1 Torr Gas Flow Regulator Valve

1 Torr 10 Torr

  • 5

PLA Single Sample Chamber Gun Chamber High Vacuum Pump Mechanical Pump 1 Torr Gas Flow Regulator Valve

1 Torr 10 Torr

  • 5

PLA Single

LV-CSEMs are restricted to a single Pressure Limiting Aperture. LV-CSEMs are restricted to a single Pressure Limiting Aperture. It must be large enough to pass the beam and small enough to limit gas flow. It must be large enough to pass the beam and small enough to limit gas flow.

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SLIDE 34

34 34

Electro ElectroScan Scan

Pressure Limiting Aperture Size Pressure Limiting Aperture Size and Beam Gas Path Length and Beam Gas Path Length

Beam Gas Path Length

2 mm 15-20 mm

ESEM LV-CSEM

BSED

Beam Gas Path Length

2 mm 15-20 mm

ESEM LV-CSEM

BSED

Beam Gas Path Length

2 mm 15-20 mm

ESEM LV-CSEM

BSED

A single aperture at the rocking point of the beam results in a A single aperture at the rocking point of the beam results in a long beam gas path length and reduced imaging current. long beam gas path length and reduced imaging current.

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SLIDE 35

35 35

Electro ElectroScan Scan

Imaging Current Losses Vs. Imaging Current Losses Vs. Pressure and BGPL Pressure and BGPL

Imaging Current - Room Temperature, Water Vapor, 20 kV Pressure % of Primary Beam Current Torr Pascals ESEM LV-CSEM BGPL = 2 mm BGPL = 20 mm 40 5320 5% 20 2660 23% 10 1330 48% 0.1% 7 931 60% 0.6% 5 665 69% 2.5% 2 266 86% 23% 1 133 93% 48% 0.5 66.5 96% 69%

The long beam gas path length reduces the current The long beam gas path length reduces the current available for imaging in an LV-CSEM available for imaging in an LV-CSEM

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SLIDE 36

36 36

Electro ElectroScan Scan

Relative Humidity Isobars Relative Humidity Isobars

Relative Humidity Isobars

5 10 15 20 25 5 10 15 20 25 Temperature (°C) Pressure (Torr)

Liquid Phase Gas Phase

100% 60% 80% 40% 20%

LV-CSEM ESEM

Relative Humidity Isobars

5 10 15 20 25 5 10 15 20 25 Temperature (°C) Pressure (Torr)

Liquid Phase Gas Phase

100% 60% 80% 40% 20%

LV-CSEM ESEM

Relative Humidity Isobars

5 10 15 20 25 5 10 15 20 25 Temperature (°C) Pressure (Torr)

Liquid Phase Gas Phase

100% 60% 80% 40% 20%

LV-CSEM ESEM

The sample chamber pressure must be at least 4.6 Torr to sustain liquid water. The sample chamber pressure must be at least 4.6 Torr to sustain liquid water.

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SLIDE 37

37 37

Electro ElectroScan Scan

Sample Dehydration Sample Dehydration

LV-CSEM 1.4 Torr 6º C T=0 min 1.4 Torr 6º C T=2 min ESEM 7 Torr 6º C T=0 min 7 Torr 6º C T=30 min

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SLIDE 38

38 38

Electro ElectroScan Scan

LV-CSEM BSE Image Resolution LV-CSEM BSE Image Resolution

ESEM Secondary Imaging ESEM Secondary Imaging LV Backscattered Imaging LV Backscattered Imaging High High Atomic Atomic Number Number Low Low Atomic Atomic Number Number

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SLIDE 39

39 39

Electro ElectroScan Scan

LV-CSEM Charge Suppression LV-CSEM Charge Suppression (BSE Images) (BSE Images)

0.2 Torr 0.9 Torr

Although less susceptible than secondary images, Although less susceptible than secondary images, backscattered images may also show charging artifacts. backscattered images may also show charging artifacts.

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SLIDE 40

40 40

Electro ElectroScan Scan

Electron Skirt X-rays Electron Skirt X-rays

2 mm

ESEM θ LV-CSEM

BSED

θ r

15-20 mm

r

Skirt Radius and Beam Gas Path Length

2 mm

ESEM θ LV-CSEM

BSED

θ r

15-20 mm

r

Skirt Radius and Beam Gas Path Length

2 mm

ESEM θ LV-CSEM

BSED

θ r

15-20 mm

r

Skirt Radius and Beam Gas Path Length

The long beam gas path length multiplies the diameter The long beam gas path length multiplies the diameter

  • f the scattered electron skirt in an LV-CSEM
  • f the scattered electron skirt in an LV-CSEM
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SLIDE 41

41 41

Electro ElectroScan Scan

Skirt X-rays Skirt X-rays

ESEM ESEM LV-CSEM LV-CSEM

The long beam gas path length in an LV-CSEM generates a broad electron skirt. The long beam gas path length in an LV-CSEM generates a broad electron skirt. Skirt electrons can generate X-rays far from the analytical target. These spectra Skirt electrons can generate X-rays far from the analytical target. These spectra were acquired from a 900 micron crystal of Epsom salt secured to an aluminum were acquired from a 900 micron crystal of Epsom salt secured to an aluminum stub with carbon paint. The C and AL peaks in the LV-CSEM spectrum confirm stub with carbon paint. The C and AL peaks in the LV-CSEM spectrum confirm the presence of a large skirt. The peaks are absent from the ESEM spectrum. the presence of a large skirt. The peaks are absent from the ESEM spectrum.

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SLIDE 42

42 42

Electro ElectroScan Scan

Nonconductive Samples Nonconductive Samples

Silicon Nitride

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SLIDE 43

43 43

Electro ElectroScan Scan

Nonconductive Samples Nonconductive Samples

Ceramic Composite

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SLIDE 44

44 44

Electro ElectroScan Scan

Nonconductive Samples Nonconductive Samples

Partially Fossilized Dinosaur Bone

slide-45
SLIDE 45

45 45

Electro ElectroScan Scan

Nonconductive Samples Nonconductive Samples

Fossil Aquatic Fern Megaspore

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SLIDE 46

46 46

Electro ElectroScan Scan

Nonconductive Samples Nonconductive Samples

Fossil Fern Spore

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SLIDE 47

47 47

Electro ElectroScan Scan

Nonconductive Samples Nonconductive Samples

Foraminifer

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SLIDE 48

48 48

Electro ElectroScan Scan

Nonconductive Samples Nonconductive Samples

Integrated Circuit Contact Hole

slide-49
SLIDE 49

49 49

Electro ElectroScan Scan

Nonconductive Samples Nonconductive Samples

Pharmaceutical Inhaler Crystals

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SLIDE 50

50 50

Electro ElectroScan Scan

Nonconductive Samples Nonconductive Samples

Artificial Sweetener Crystals

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SLIDE 51

51 51

Electro ElectroScan Scan

Nonconductive Samples Nonconductive Samples

Rouge on Nylon

slide-52
SLIDE 52

52 52

Electro ElectroScan Scan

Hydrated Samples Hydrated Samples

Orchid Petal

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SLIDE 53

53 53

Electro ElectroScan Scan

Hydrated Samples Hydrated Samples

Poinsettia Leaf

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SLIDE 54

54 54

Electro ElectroScan Scan

Hydrated Samples Hydrated Samples

Poinsettia Pollen

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SLIDE 55

55 55

Electro ElectroScan Scan

Hydrated Samples Hydrated Samples

Passion Flower Pollen

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SLIDE 56

56 56

Electro ElectroScan Scan

Hydrated Samples Hydrated Samples

Stomata of an Aloe Vera Leaf

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SLIDE 57

57 57

Electro ElectroScan Scan

Hydrated Samples Hydrated Samples

Root Hairs of a Beet Seedling

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SLIDE 58

58 58

Electro ElectroScan Scan

Hydrated Samples Hydrated Samples

Rat Tooth

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SLIDE 59

59 59

Electro ElectroScan Scan

Hydrated Samples Hydrated Samples

Live Aphid

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SLIDE 60

60 60

Electro ElectroScan Scan

Hydrated Samples Hydrated Samples

Sweat Pore, Porcine Abdominal Skin

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SLIDE 61

61 61

Electro ElectroScan Scan

Hydrated Samples Hydrated Samples

Finger Tip

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SLIDE 62

62 62

Electro ElectroScan Scan

Hydrated Samples Hydrated Samples

Human Hair with Water Droplets

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SLIDE 63

63 63

Electro ElectroScan Scan

Hydrated Samples Hydrated Samples

Wet Paper Fibers

slide-64
SLIDE 64

64 64

Electro ElectroScan Scan

Hydrated Samples Hydrated Samples

Bacteria and Red Blood Cells on Tooth Root Tissue

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SLIDE 65

65 65

Electro ElectroScan Scan

Hydrated Samples Hydrated Samples

Water Film on Copper Grid

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SLIDE 66

66 66

Electro ElectroScan Scan

Contaminating Samples Contaminating Samples

Unknown Crystallized Structure Found in Oil Saturated Sandstone

slide-67
SLIDE 67

67 67

Electro ElectroScan Scan

Contaminating Samples Contaminating Samples

Droplets of Oil and Water on an Oil Field Core Sample

slide-68
SLIDE 68

68 68

Electro ElectroScan Scan

Contaminating Samples Contaminating Samples

Crystal-like Fibers in Water Saturated Sandstone

slide-69
SLIDE 69

69 69

Electro ElectroScan Scan

Contaminating Samples Contaminating Samples

Metal Particles in Uncured Resin

slide-70
SLIDE 70

70 70

Electro ElectroScan Scan

Contaminating Samples Contaminating Samples

Outgassing Antacid Particles Dissolving in Water

slide-71
SLIDE 71

71 71

Electro ElectroScan Scan

Contaminating Samples Contaminating Samples

Bacon Bit

slide-72
SLIDE 72

72 72

Electro ElectroScan Scan

Delicate Samples Delicate Samples

Fungus on a Pine Needle

slide-73
SLIDE 73

73 73

Electro ElectroScan Scan

Delicate Samples Delicate Samples

Fungal Hyphae with Calcium Oxalate Crystals

slide-74
SLIDE 74

74 74

Electro ElectroScan Scan

Delicate Samples Delicate Samples

Bread Mold

slide-75
SLIDE 75

75 75

Electro ElectroScan Scan

Delicate Samples Delicate Samples

Moth Wing Scales

slide-76
SLIDE 76

76 76

Electro ElectroScan Scan

Coating Interference Coating Interference

Styrofoam at 9.1kV

slide-77
SLIDE 77

77 77

Electro ElectroScan Scan

Coating Interference Coating Interference

Styrofoam at 24 kV

slide-78
SLIDE 78

78 78

Electro ElectroScan Scan

Coating Interference Coating Interference

Lung Tissue Labeled with 20 nm Gold Particles

slide-79
SLIDE 79

79 79

Electro ElectroScan Scan

Phase Transitions Phase Transitions

Pure Silicon Melted and Recrystallized at 1400º+ C in the ESEM

slide-80
SLIDE 80

80 80

Electro ElectroScan Scan

Phase Transitions Phase Transitions

Solder on Copper Reflowed in ESEM

slide-81
SLIDE 81

81 81

Electro ElectroScan Scan

Phase Transitions Phase Transitions

KCL Crystals grown from Gas in ESEM at 600º C

slide-82
SLIDE 82

82 82

Electro ElectroScan Scan

Phase Transitions Phase Transitions

Sublimating Camphor

slide-83
SLIDE 83

83 83

Electro ElectroScan Scan

Phase Transitions Phase Transitions

Ice Crystallizing from Vapor in the ESEM

slide-84
SLIDE 84

84 84

Electro ElectroScan Scan

Phase Transitions Phase Transitions

HCL Crystallizing over Ice Film on Pyrex

slide-85
SLIDE 85

85 85

Electro ElectroScan Scan

Hydration Processes Hydration Processes

Salt Dissolving in Water Condensed from ESEM Environment

slide-86
SLIDE 86

86 86

Electro ElectroScan Scan

Hydration Processes Hydration Processes

Cement Wetted by Water from ESEM Environment

slide-87
SLIDE 87

87 87

Electro ElectroScan Scan

Oxidation/Corrosion Oxidation/Corrosion

Iron Oxidizing in the ESEM

slide-88
SLIDE 88

88 88

Electro ElectroScan Scan

Oxidation/Corrosion Oxidation/Corrosion

Iron Sulfide Crystals Grown on Stainless Steel

slide-89
SLIDE 89

89 89

Electro ElectroScan Scan

Thermal/Mechanical/Chemical Thermal/Mechanical/Chemical Stress Stress

Plastic Composite Etched by Liquid Toluene

slide-90
SLIDE 90

90 90

Electro ElectroScan Scan

Thermal/Mechanical/Chemical Thermal/Mechanical/Chemical Stress Stress

Crack Initiation and Propagation at the Fiber Matrix Interface of Silicon Carbide Reinforced Composite in a High Temperature Oxidizing Environment

slide-91
SLIDE 91

91 91

Electro ElectroScan Scan

Thermal/Mechanical/Chemical Thermal/Mechanical/Chemical Stress Stress

Tensile Failure in Polypropylene Reinforced Cement

slide-92
SLIDE 92

92 92

Electro ElectroScan Scan

Thermal/Mechanical/Chemical Thermal/Mechanical/Chemical Stress Stress

Cracking in Carbon-Carbon Composite at 1300º C