Transport of Secondary Electrons Through a Film of Condensed Water; Implications for Imaging Wet Samples

We have performed a theoretical and experimental study of the the effect that a surface layer of condensed water has on the emission of secondary electrons from the surface. This is an issue of considerable interest to users of the Environmental SEM (ESEM) when imaging wet samples. Previous work has been performed to investigate the effect of a layer of water on back scattered electrons (BSE), but secondary electron (SE) imaging is more commonly used in ESEM, so an understanding of the interactions of SE with water is important. The aim of this work is to quantify the thickness of water through which imaging is possible, by considering both the interactions of secondary electrons with the water, and the interactions of the water layer with the sample, which may affect the secondary electron emission coefficient, δ.The effects that a surface layer of water may have on electron emission from a sample surface can be split into three regimes.

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Effects of Space Charge on ESEM Gas Amplification

Microscopy and Microanalysis ◽

10.1017/s1431927600009934 ◽

1997 ◽

Vol 3 (S2) ◽

pp. 609-610 ◽

Cited By ~ 1

Author(s):

B.L. Thiel ◽

M.R. Hussein-Ismail ◽

A.M. Donald

Keyword(s):

Electric Field ◽

Electrostatic Field ◽

Secondary Electron ◽

Sample Surface ◽

Cascade Process ◽

Secondary Electrons ◽

Positive Ions ◽

Space Charges ◽

Cascade Amplification ◽

Environmental Sem

We have performed a theoretical investigation of the effects of space charges in the Environmental SEM (ESEM). The ElectroScan ESEM uses an electrostatic field to cause gas cascade amplification of secondary electron signals. Previous theoretical descriptions of the gas cascade process in the ESEM have assumed that distortion of the electric field due to space charges can be neglected. This assumption has now been tested and shown to be valid.In the ElectroScan ESEM, a positively biased detector is located above the sample, creating an electric field on the order of 105 V/m between the detector and sample surface. Secondary electrons leaving the sample are cascaded though the gas, amplifying the signal and creating positive ions. Because the electrons move very quickly through the gas, they do not accumulate in the specimen-to-detector gap. However, the velocity of the positive ions is limited by diffusion.

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Spatial variations of radio frequency plasma density caused by a step‐change of secondary electron emission coefficient

Journal of Applied Physics ◽

10.1063/1.359452 ◽

1995 ◽

Vol 77 (9) ◽

pp. 4293-4301 ◽

Cited By ~ 4

Author(s):

Weilu Xu ◽

Paul J. Sides

Keyword(s):

Radio Frequency ◽

Plasma Density ◽

Electron Emission ◽

Secondary Electron ◽

Secondary Electron Emission ◽

Step Change ◽

Radio Frequency Plasma ◽

Emission Coefficient ◽

Secondary Electron Emission Coefficient ◽

Frequency Plasma

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Discussion on the influences of townsend ionization coefficient α and secondary electron emission coefficient γ on the characteristics of DBD

2016 IEEE International Conference on Plasma Science (ICOPS) ◽

10.1109/plasma.2016.7534383 ◽

2016 ◽

Author(s):

Congwei Yao ◽

Zhengshi Chang ◽

Hengchi Ma ◽

Ping Li ◽

Guimin Xu ◽

...

Keyword(s):

Electron Emission ◽

Secondary Electron ◽

Secondary Electron Emission ◽

Emission Coefficient ◽

Ionization Coefficient ◽

Secondary Electron Emission Coefficient

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MAXIMUM SECONDARY ELECTRON YIELDS FROM SEMICONDUCTORS AND INSULATORS

Surface Review and Letters ◽

10.1142/s0218625x17500457 ◽

2016 ◽

Vol 24 (04) ◽

pp. 1750045 ◽

Cited By ~ 6

Author(s):

A. G. XIE ◽

Z. H. LIU ◽

Y. Q. XIA ◽

M. M. ZHU

Keyword(s):

Electron Emission ◽

Secondary Electron ◽

Maximum Yield ◽

Secondary Electron Emission ◽

High Energy ◽

Secondary Electrons ◽

Backscattered Electrons ◽

Universal Formula ◽

Yield Formula ◽

Primary Electrons

Based on the processes and characteristics of secondary electron emission and the formula for the yield due to primary electrons hitting on semiconductors and insulators, the universal formula for maximum yield [Formula: see text] due to primary electrons hitting on semiconductors and insulators was deduced, where [Formula: see text] is the maximum ratio of the number of secondary electrons produced by primary electrons to the number of primary electrons. On the basis of the formulae for primary range in different energy ranges of [Formula: see text], characteristics of secondary electron emission and the deduced universal formula for [Formula: see text], the formulae for [Formula: see text] in different energy ranges of [Formula: see text] were deduced, where [Formula: see text] is the primary incident energy at which secondary electron yields from semiconductors and insulators, [Formula: see text], are maximized to maximum secondary electron yields from semiconductors and insulators, [Formula: see text]; and [Formula: see text] is the maximum ratio of the number of total secondary electrons produced by primary electrons and backscattered electrons to the number of primary electrons. According to the deduced formulae for [Formula: see text], the relationship among [Formula: see text], [Formula: see text] and high-energy back-scattering coefficient [Formula: see text], the formulae for parameters of [Formula: see text] and the experimental data as well as the formulae for [Formula: see text] in different energy ranges of [Formula: see text] as a function of [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] were deduced, where [Formula: see text] and [Formula: see text] are the original electron affinity and the width of forbidden band, respectively. The scattering of [Formula: see text] was analyzed, and calculated [Formula: see text] values were compared with the values measured experimentally. It was concluded that the deduced formulae for [Formula: see text] were found to be universal for [Formula: see text].

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CRYSTALLOGRAPHIC ORIENTATION INFLUENCE ON SECONDARY ELECTRON EMISSION COEFFICIENT OF A SINGLE CRYSTAL OF SYNTHETIC DIAMOND

IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA ◽

10.6060/tcct.20165908.30y ◽

2018 ◽

Vol 59 (8) ◽

pp. 21

Author(s):

Vladimir Yu. Sadovoy ◽

Vladimir D. Blank ◽

Sergey A. Terentiev ◽

Dmitriy V. Teteruk ◽

Sergey Yu. Troschiev

Keyword(s):

Single Crystal ◽

Electron Emission ◽

Crystallographic Orientation ◽

Beam Energy ◽

Secondary Electron ◽

Secondary Electron Emission ◽

Primary Beam ◽

Emission Coefficient ◽

Secondary Electron Emission Coefficient ◽

Single Crystal Diamond

Dependence of secondary electron emission coefficient on the chosen crystallographic orientation for a synthetic single crystal diamond of type IIb, grown up by method of a temperature gradient, was investigated. The type IIb of single crystal diamond was chosen because of wide applicability in different areas of microelectronics and the semiconductor properties. Quantitative measurements of secondary electron emission coefficients with energy of primary beam about 7 keV and above for various crystallographic orientations was carried out: the highest coefficient of secondary electronic emission are recorded for the direction (100), cubic sector, and also in intergrowth area that is confirmed by a picture of distribution of the luminescence intensity for various sectors of a single crystal received by means of true secondary electrons detector of scanning electron microscope. The results for (100) area are outstanding: 8.18 at primary beam energy of 7 keV, 10.13 at 10 keV, 49.78 at 30 keV. The results for intergrowth area are similar: 10.10 at primary beam energy of 7 keV, 13.56 at 10 keV, 64.41 at 30 keV. The crystallographic directions (111) have shown secondary electron emission coefficient 4-6 times lower in comparison with (100) and intergrowth area: 2.54 on the average at primary beam energy of 7 keV, 2.75 at 10 keV, 10.03 at 30 keV. The non-standard behavior of secondary electron emission coefficient at the high energy primary beam for all orientations of single crystal diamond is shown: increase in secondary electron emission coefficient with increase in energy of primary beam. At the moment the reason of such behavior is not clear up to the end and since this fact causes a great interest of researchers, considerably expands applicability of the existing devices and detectors due to replacement of a functional element on diamond one, and also opens big opportunities for formation of new field of microelectronics, this facts demand further in-depth study by means of various methods of the structural and surface analysis.

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