Scanning Electron Microscopy and X-Ray Microanalysis

356

21

Co

unts Ag

0.0 2.0 4.0 6.0 8.0

Photon energy (keV)

10.0 12.0 14.0 16.0 18.0 20

Ti = 0.000005 Ta

E 0 = 20 keV

8% Deadtime

Ti

Ag = 0.000003

2T

aMa,b

. Fig. 21.17 Measurement of
high purity Ta surrounded by Ag
(doped epoxy) and titanium; Ag
or Ti are both observed at very
low levels: Ag, k = 0.000003; Ti,
k = 0.000005

EDS

detector

window

Collimator &

electron trap

Final

lens

Chamber

wall

Aperture

scattering

Conventional SEM,

pathological scattering

Spectrum from strong

topographic scatterer, e.g., SrF2,

surrounded by different

materials, e.g., Pt, Ti

Green =

Extent of

specimen

X-ray sources

NOT excluded by

collimator

Multi-material “topographic scatter” test specimen

. Fig. 21.18 Modification of
the “in-hole” configuration with a
three-dimensional target to
produce the effects of
backscattering from inclined
surfaces

Chapter 21 · Trace Analysis by SEM/EDS