Secondary Electron Emission and Photoemission from Negative Electronaffinity Semiconductor with Large Mean Escape Depth of Excited Electrons

2021 ◽  
Author(s):  
Ai-Gen Xie ◽  
Hong-Jie Dong ◽  
Yi-Fan Liu ◽  
Yue-Lin Gan
Keyword(s):  
Electron Emission ◽  
Secondary Electron ◽  
Secondary Electron Emission ◽  
Escape Depth ◽  
Mean Escape Depth

Thickness Dependence in Secondary Electron Emission from Carbon

1975 ◽  
Vol 33 ◽  
pp. 100-101
Author(s):  
D. Voreades
Keyword(s):  
Electron Emission ◽  
Secondary Electron ◽  
Secondary Electron Emission ◽  
Secondary Emission ◽  
Secondary Electrons ◽  
Emission Process ◽  
Backscattered Electrons ◽  
Escape Depth ◽  
Mode Of Operation ◽  
Scanning Electron

Secondary electrons are used in making topographical pictures of specimens in the scanning electron microscope. A better understanding of the secondary emission process will contribute in improving the resolution in this mode of operation.Recent experiments have indicated first that the escape depth of secondary electrons is a few atomic layers at the surface of the solid and second that the backscattered electrons are much more efficient in producing secondaries than the incoming ones. The results vary considerably. However, any model that one makes, for example similar to that of Jonker, consistent with these recent experimental results, will have the thickness as an important parameter.

Formulae for maximum yield and mean escape depth of secondary electrons emitted from metals

2017 ◽  
Vol 31 (26) ◽  
pp. 1750239 ◽  
Author(s):  
Ai-Gen Xie ◽  
Yu-Qing Xia ◽  
Xing Wang ◽  
Hao-Yu Liu ◽  
Shi Cheng
Keyword(s):  
Secondary Electron ◽  
Maximum Yield ◽  
Secondary Electron Emission ◽  
Average Energy ◽  
Primary Energy ◽  
Atomic Weight ◽  
Escape Probability ◽  
Secondary Electrons ◽  
Escape Depth ◽  
Mean Escape Depth

Based on the characteristics of secondary electron emission, the former formulae for the maximum yield of metals [Formula: see text] and primary range in the energy range of [Formula: see text] eV, relation [Formula: see text] among secondary electron escape probability [Formula: see text], average energy required to produce an internal secondary electron [Formula: see text], [Formula: see text], primary energy of [Formula: see text] ([Formula: see text] and parameter [Formula: see text] was deduced. On the basis of [Formula: see text] and the former formula for [Formula: see text], relation [Formula: see text] among mean escape depth of secondary electrons emitted from metals [Formula: see text], atomic number [Formula: see text], back-scattering coefficient [Formula: see text], material density [Formula: see text], [Formula: see text], atomic weight [Formula: see text] and [Formula: see text] was deduced. According to the deduced [Formula: see text], the formula for the ratio of [Formula: see text] to [Formula: see text] and experimental ratio of [Formula: see text] to [Formula: see text], relation [Formula: see text] among [Formula: see text], original work function [Formula: see text] and [Formula: see text] were empirically obtained. According to the characteristics of metal surface, [Formula: see text], [Formula: see text] and [Formula: see text], the formula for [Formula: see text] as a function of [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] and that for [Formula: see text] as a function of [Formula: see text], [Formula: see text] and [Formula: see text] were deduced, respectively. The influences of surface change on [Formula: see text] and [Formula: see text] were analyzed. Calculated [Formula: see text] and [Formula: see text] were compared with the corresponding experimental ones. It was concluded that the deduced formulae for [Formula: see text] and [Formula: see text] can be used to estimate [Formula: see text] and [Formula: see text], respectively.

Historical Introduction

1977 ◽  
Vol 35 ◽  
pp. 2-5
Author(s):  
R. D. Heidenreich
Keyword(s):  
Electron Emission ◽  
Secondary Electron ◽  
Secondary Electron Emission ◽  
50Th Anniversary ◽  
Secondary Emission ◽  
Wave Nature ◽  
Nobel Prize In Physics ◽  
Primary Electrons ◽  
The U.S ◽  
Mutual Agreement

This program has been organized by the EMSA to commensurate the 50th anniversary of the experimental verification of the wave nature of the electron. Davisson and Germer in the U.S. and Thomson and Reid in Britian accomplished this at about the same time. Their findings were published in Nature in 1927 by mutual agreement since their independent efforts had led to the same conclusion at about the same time. In 1937 Davisson and Thomson shared the Nobel Prize in physics for demonstrating the wave nature of the electron deduced in 1924 by Louis de Broglie.The Davisson experiments (1921-1927) were concerned with the angular distribution of secondary electron emission from nickel surfaces produced by 150 volt primary electrons. The motivation was the effect of secondary emission on the characteristics of vacuum tubes but significant deviations from the results expected for a corpuscular electron led to a diffraction interpretation suggested by Elasser in 1925.

SEM and Auger microanalysis studies of Cu-Be dynode surfaces at each activation condition

1978 ◽  
Vol 36 (1) ◽  
pp. 524-525
Author(s):  
T. Koshikawa ◽  
Y. Fujii ◽  
E. Sugata ◽  
F. Kanematsu
Keyword(s):  
Electron Emission ◽  
Secondary Electron ◽  
Secondary Electron Emission ◽  
Life Time ◽  
Activation Process ◽  
Beam Diameter ◽  
Activation Temperature ◽  
Electron Multiplier ◽  
Activation Condition ◽  
Activation Conditions

The Cu-Be alloys are widely used as the electron multiplier dynodes after the adequate activation process. But the structures and compositions of the elements on the activated surfaces were not studied clearly. The Cu-Be alloys are heated in the oxygen atmosphere in the usual activation techniques. The activation conditions, e.g. temperature and O2 pressure, affect strongly the secondary electron yield and life time of dynodes.In the present paper, the activated Cu-Be dynode surfaces at each condition are investigated with Scanning Auger Microanalyzer (SAM) (primary beam diameter: 3μmϕ) and SEM. The commercial Cu-Be(2%) alloys were polished with Cr2O3 powder, rinsed in the distilled water and set in the vacuum furnance.Two typical activation condition, i.e. activation temperature 730°C and 810°C in 5x10-3 Torr O2 pressure were chosen since the formation mechanism of the BeO film on the Cu-Be alloys was guessed to be very different at each temperature from the results of the secondary electron emission measurements.

SEM analysis of DC magnetron sputtered beryllium films

1988 ◽  
Vol 46 ◽  
pp. 960-961
Author(s):  
E. F. Lindsey ◽  
C. W. Price ◽  
E. L. Pierce ◽  
E. J. Hsieh
Keyword(s):  
Fine Structure ◽  
Electron Emission ◽  
Secondary Electron ◽  
Low Voltage ◽  
Ion Beam ◽  
Secondary Electron Emission ◽  
Sem Analysis ◽  
Fused Silica ◽  
Grain Structure ◽  
Silica Substrate

Columnar structures produced by DC magnetron sputtering can be altered by using RF biased sputtering or by exposing the film to nitrogen pulses during sputtering, and these techniques are being evaluated to refine the grain structure in sputtered beryllium films deposited on fused silica substrates. Beryllium is brittle, and fractures in sputtered beryllium films tend to be intergranular; therefore, a convenient technique to analyze grain structure in these films is to fracture the coated specimens and examine them in an SEM. However, fine structure in sputtered deposits is difficult to image in an SEM, and both the low density and the low secondary electron emission coefficient of beryllium seriously compound this problem. Secondary electron emission can be improved by coating beryllium with Au or Au-Pd, and coating also was required to overcome severe charging of the fused silica substrate even at low voltage. The coating structure can obliterate much of the fine structure in beryllium films, but reasonable results were obtained by using the high-resolution capability of an Hitachi S-800 SEM and either ion-beam coating with Au-Pd or carbon coating by thermal evaporation.

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