scholarly journals Direct measurement of electron beam scattering in the environmental scanning electron microscope using phosphor imaging plates

Scanning ◽  
2000 ◽  
Vol 22 (3) ◽  
pp. 167-172 ◽  
Author(s):  
Scott A. Wight ◽  
Cynthia J. Zeissler
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Direct Measurement ◽  
Environmental Scanning Electron Microscope ◽  
Environmental Scanning ◽  
Beam Scattering ◽  
Imaging Plates ◽  
Scanning Electron

Review of Techniques for Overcoming XEDS Problems in the Environmental Scanning Electron Microscope

1997 ◽  
Vol 3 (S2) ◽  
pp. 1207-1208
Author(s):  
John Mansfield
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Primary Electron ◽  
Environmental Scanning Electron Microscope ◽  
Significant Fraction ◽  
Environmental Scanning ◽  
Primary Electron Beam ◽  
Environmental Sem ◽  
Scanning Electron

Full characterization of materials in the environmental scanning electron microscope (Environmental SEM) often requires chemical analysis by X-ray energy dispersive spectroscopy (XEDS). However, a major problem arises because the spatial resolution of the XEDS signal is severely degraded by the gaseous environment in the sample chamber. The significant fraction of the primary electron beam is scattered after it passes through the final pressure limiting aperture and before it strikes the sample. Bolon and Griffin have both published data that illustrates this effect very well. Bolon revealed that 45% of the primary electron beam was scattered by more than 25μm in an Environmental SEM operating at an accelerating voltage of 30kV, with a water vapor pressure of 3Torr and a working distance of 15mm. Griffin’s work demonstrated that even at higher voltages (30 kV), shorter working distances (<10mm) and lower chamber pressures (2Torr), there is a significant fraction of the electron beam scattered out to over 400 μm away from the point where the primary beam strikes the sample.

What Do We Need to Look Out for When Doing Energy Dispersive Xray Analysis in the Environmental Scanning Electron Microscope?

1999 ◽  
Vol 5 (S2) ◽  
pp. 290-291
Author(s):  
Scott Wight
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Quantitative Analysis ◽  
Scanning Electron Microscope ◽  
High Vacuum ◽  
Environmental Scanning Electron Microscope ◽  
Energy Dispersive ◽  
Environmental Scanning ◽  
Eds Analysis ◽  
Scanning Electron

The environmental scanning electron microscope (ESEM) is not typically used for quantitative analysis by energy dispersive x-ray spectrometry (EDS) because the electron beam is scattered by the chamber gas forming a broad tail or skirt rather than a focused spot. Scattered electrons can contribute x-rays from areas not directly under the beam, which compromises the spectrum for quantitative analysis. For specimens compatible with high vacuum, quantitative EDS analysis in a conventional electron microscope is preferred. However, the ESEM has found its niche in providing a vehicle for investigating those specimens that for any of a variety of reasons are not suitable for high vacuum electron microscopy and microanalysis. For these specimens, it is important that we find the most accurate way to perform EDS analysis in the low vacuum environment.Research has focused on reducing, accounting for, predicting, or measuring the electron scattering on a simplified system. Instrumental tricks to reduce the scattering of the primary electron beam have been reported in the past.

Sign in / Sign up

Export Citation Format

Share Document