Low-Voltage Scanning Electron Microscopy in polymer characterization

1987 ◽  
Vol 45 ◽  
pp. 468-469 ◽  
Author(s):  
V. K. Berry
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Low Voltage ◽  
Polymer Surfaces ◽  
Conducting Materials ◽  
Theoretical Considerations ◽  
Voltage Scanning ◽  
Beam Damage ◽  
Scanning Electron

The application of low voltage scanning electron microscopy (LVSEM) to the characterization of polymers and non-conducting materials, other than semiconductors, has not been well explored yet. Some of the theoretical considerations and practical limitations which prevented the development of commercial instruments have mostly been addressed with the result that machines are now available which are optimized for low voltage (≥ 0.5 kV) operation. The advantages of working at low voltages are beginning to be recognized outside the semi-conductor industry. When we image uncoated polymer surfaces at low beam energies (0.5-1.5 kV), no beam damage or charging artifacts are experienced, because in this region the emitted electrons are equal to or more than the incident electrons and there is no deposition of charge underneath the surface due to the lower penetration of the incident electrons.

Low-Voltage Scanning Electron Microscopy Investigation of Polymers

1988 ◽  
Vol 46 ◽  
pp. 220-221
Author(s):  
V. K. Berry
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Low Voltage ◽  
Morphological Characterization ◽  
Transmission Electron ◽  
Conducting Materials ◽  
Voltage Scanning ◽  
Scanning Electron

The morphological characterization of any polymer blend plays an important part in the development of a new blend system because the properties of blends are dictated by phase morphology which is dependent upon the chemistry and the processing conditions. Light microscopy, scanning electron microscopy and transmission electron microscopy are the most commonly used microscopical techniques for morphological characterization. Transmission electron microscopy techniques provide the best resolution (≈ 0.3 nm) but are limited in the size of sample area and require elaborate sample preparation procedures. Surface charging and beam damage problems have been some of the drawbacks of conventional scanning electron microscopy with non-conducting materials like polymers.The use of low accelerating voltage scanning electron microscopy (LVSEM) in the characterization of polymers and other non-conducting materials is beginning to be recognized.

Low-voltage Scanning Electron Microscopy of polymers

1986 ◽  
Vol 44 ◽  
pp. 676-677 ◽  
Author(s):  
O. W. Vaz ◽  
S. J. Krause
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Low Voltage ◽  
Polymer Surface ◽  
Image Distortion ◽  
Crossover Point ◽  
Voltage Scanning ◽  
Beam Damage ◽  
Scanning Electron

Scanning electron microscopy (SEM) of polymers at routine operating voltages of 15 to 25 keV can lead to beam damage and sample image distortion due to charging. These problems may be avoided by imaging polymer samples at a “crossover point”, which is located at low accelerating voltages (0.1 to 2.0 keV), where the number of electrons impinging on the sample are equal to the number of outgoing electrons emerging from the sample. This condition permits the polymer surface to remain electrically neutral and prevents image distortion due to “charging” effects. In this research we have examined Teflon (polytetrafluorethylene) samples and studied the effects of accelerating voltage and sample tilting on charging phenomena. We have also determined the approximate position of the “crossover point”.

LOW-VOLTAGE AND ULTRA-LOW-VOLTAGE SCANNING ELECTRON MICROSCOPY OF SEMICONDUCTOR SURFACES AND DEVICES

2002 ◽  
Vol 16 (28n29) ◽  
pp. 4387-4394 ◽  
Author(s):  
JINGYUE LIU
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Low Voltage ◽  
Image Resolution ◽  
Sem Images ◽  
Conducting Materials ◽  
Low Energies ◽  
Low Energy Electrons ◽  
Voltage Scanning ◽  
Scanning Electron

Low-voltage scanning electron microscopy (LV-SEM) enables us to directly examine non-conducting materials with high spatial resolution. Although use of ultra-low-energy electrons can provide further advantages for characterizing delicate samples, lens aberrations rapidly deteriorates the image resolution. The combined use of a retarding field and the probe-forming lens system can improve the image resolution for electrons with very low energies. In commercially available FEG-SEMs, the retarding field can simply be constructed by applying a negative potential to the specimen. Interesting contrast variations have been observed in ultra-low-voltage SEM images. In this short communication, we discuss the application of LV-SEM to examining semiconductor devices and also the recent development of the ultra-low-voltage SEM technique.

Surface morphology characterization of industrial polymers by low-voltage scanning electron microscopy

1991 ◽  
Vol 49 ◽  
pp. 1036-1037
Author(s):  
V. K. Berry
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Low Voltage ◽  
Collection Efficiency ◽  
Steady Increase ◽  
Brightness Field ◽  
Morphology Characterization ◽  
Voltage Scanning ◽  
Scanning Electron

There has been an increase in awareness in low voltage scanning electron microscopy (LVSEM) of polymers in recent years because not only is it possible to use uncoated or very lightly coated (1-5nm) polymer samples but also due to an inherent advantage of limited beam damage of polymer samples by low energy beams. A steady increase in the use of low accelerating voltages for characterizing polymers has been made possible due to some major developments, such as high brightness field emission source, better lens and column design to minimize lens aberrations, and newer and improved detector systems with higher collection efficiency, incorporated by instrument manufacturers in their newer commercial models in recent years. Although there is still room for further improvements, the described instrumental changes have made possible the appreciation of LVSEM in characterization of polymers and non-conducting, beam sensitive materials.

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