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Since the early 1990s, researchers have improved low-voltage scanning electron microscopy (LVSEM) [1 - 5]. Their contributions have been mainly on LVSEM instrumentation [6], lateral resolution [7 - 9], and its application in the life sciences [10]. All studies have underlined the advantage of LVSEM over conventional scanning electron microscopy (SEM) in terms of increased surface sensitivity, minimization of charging, and radiation damage effects.
On the other hand, the probe diameter, which determines the spatial resolution of SEM, is dominated by chromatic aberration in the low-voltage regime [11].
It is interesting to mention that both LVSEM and CCVC pattern of e-beam testing work in the medium accelerating voltage region with weak positive charging to avoid strong negative charging at high accelerating voltages.
[1] Pawley, J.B. (1992) LVSEM for high resolution topographic and density
contrast imaging. Adv. Electron. Electron. Phys. 83, 203–274.
[2] Reimer, L. (1993) Image Formation in Low-Voltage Scanning Electron Microscopy.
SPIE Optical Engineering Press, Bellingham, WA.
[3] Joy, D.C. & Joy, C.S. (1996) Low voltage scanning electron microscopy.
Micron 27, 247–263.
[4] Newbury, D.E., Joy, D.C., Echlin, P. & Fiori, C.E., eds (2003) Advances Scanning
Electron Microscopy, 3rd edn. Plenum Press, New York.
[5] Mullerova, I. & Frank, L. (2003) Scanning low-energy electron microscopy.
Adv. Imaging Electron Phys. 128, 309–443.
[6]
Joy, D.C., Prasad, M.S. & Meyer, H.M. (2004) Experimental secondary
electron spectra under SEM conditions. J. Microsc. 218, 77–85.
[7] Plies, E. (1994) Electron optics of low-voltage electron beam testing and
inspection. Adv. Inopt. Electron Microsc. 13, 123–242.
[8] Frank, L. (1996) Real image resolution of SEM and LVSEM and its optimisation.
Ultramicroscopy 62, 261–269.
[9] Mullerova, I. (2001) Imaging of specimens at optimized low and very low
energies in scanning electron microscopes. Scanning 23, 379–394.
[10] Newbury, D.E., Joy, D.C., Echlin, P. & Fiori, C.E., eds (2003) Advances Scanning
Electron Microscopy, 3rd edn. Plenum Press, New York.
[11] Plies, E. (1994) Electron optics of low-voltage electron beam testing and
inspection. Adv. Inopt. Electron Microsc. 13, 123–242.
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