Scanning Electron Microscopy and X-Ray Microanalysis

550

Scanning electron microscope (SEM)
instrumentation (cont.)

• electron optical parameters
  
  
  • astigmatism 85–87
  
  
  • beam convergence angle, α 80–81
  
  
  • beam current 79–80
  
  
  • beam current density 80
  
  
  • beam diameter 79
  
  
  • beam energy 78–79
  
  
  • beam solid angle 81–83
  
  
  • electron optical brightness, β 83
  
  
  • focus 83–87
  
  
  
  


• imaging modes 87–88
  
  
  • high-current mode 90–92
  
  
  • high mode 88–90
  
  
  • low-voltage mode 94–95
  
  
  • resolution mode 93–94
  
  
  
  


• secondary electron detectors
  
  
  • Everhart–Thornley detector 99–100
  
  
  • through-the-lens (TTL) electron
    detectors 100
  
  
  
  


• specimen current 100–101
  Scanning electron microscopist and X-ray
  microanalyst (SEMXM) 204
  Scanning transmission electron microscope
  (STEM) image 175–176
  Secondary electron energy
  spectrum 34–35
  Secondary electrons (SE) 2, 549, vii


• angular distribution of 39–40


• energy distribution 34–35


• escape depth 35–37


• origin 34


• spatial characteristics of 40–43


• yield vs. atomic number 37–38


• yield vs. beam energy 40


• yield vs. specimen tilt 38–39
  Secondary electron yield data 553–584
  Secondary yields 549
  SEM/EDS


• limits of detection for 358–359


• remote excitation sources 370–373
  Semiconductors 493–494

Shallow surface relief 222–224

Silicon drift detector (SDD)

• low X-ray flux 250–251


• moderate resolution 251


• output count rate with live-time dose
  249–250


• resolution and peak position stability 250
  Single pixel measurement 222
  Spatial distribution, backscattered electrons


• depth distribution 26–28


• Monte Carlo simulation 25


• radial distribution 28–29
  Spectrum imaging (SI) xi
  Stopping powers 549–550

T

Thin section analysis 353–355

3D viewer plugin tool 218, 219

Transmission Kikuchi diffraction (TKD)

517–518

V

Variable pressure scanning electron microscopy

(VPSEM) vii

• contrast in 200–201


• conventional SEM high vacuum environment
  
  
  • beam integrity 190
  
  
  • difference from 190–191
  
  
  • Everhart–Thornley secondary electron
    detector 190
  
  
  • minimizing contamination 190
  
  
  • stable electron source operation 190
  
  
  
  


• EDS collimator 456–458


• elevated pressure microscopy, detectors for
  
  
  • backscattered electrons, passive scintillator
    detector 198–199
  
  
  • secondary electrons, gas amplification
    detector 199–200
  
  
  
  


• favorable sample characteristics 461–462


• gas scattering effects in 452–456, 460–461
  
  
  • scanning electron microscopy at elevated
    pressures
    
    
    • focused electron beam 193–196
    
    
    • image resolution 196–198
    
    
    • specimen charging 191–192
    
    
    • water environment of specimen 192–193
    
    
    
    
  
  
  • solve practical problems 461
  
  
  • unfavorable sample characteristics 462–468
  
  
  • X-ray spectrometry 458–460
  
  
  
  

X

X-ray ionization cross sections 550

X-rays

• characteristic of
  
  
  • families 50–51
  
  
  • fluorescence yield 48–50
  
  
  • intensity 53–56
  
  
  • isolated atoms 53–54
  
  
  • nomenclature 51
  
  
  • origin 46–47
  
  
  • thick, solid specimens 55–56
  
  
  • thin foils 54–55
  
  
  • weights of lines 51–53
  
  
  
  


• continuum (bremsstrahlung) 56–57
  
  
  • absorption 65–75
  
  
  • continuum intensity 57–58
  
  
  • depth distribution function,Φ(ρz) 64–65
  
  
  • electron-excited X-ray spectrum 58–59
  
  
  • fluorescence 75–76
  
  
  • Monte Carlo simulation 62–63
  
  
  • range of 60–62
    X-ray spectrum imaging (XSI)
  
  
  
  


• compositional mapping 429–431
  
  
  • EDS dead-time 441–443
  
  
  • elemental mapping data collection
    441–450
  
  
  • flash mapping 444–445
  
  
  • high count mapping 445–450
  
  
  • pixel density 443–444
  
  
  • pixel dwell time 444–450
  
  
  
  


• particle analysis 414–415

Index