scholarly journals Investigation of the Effect of Structural Properties of a Vertically Standing CNT Cold Cathode on Electron Beam Brightness and Resolution of Secondary Electron Images

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1918
Author(s):  
Ha Rim Lee ◽  
Da Woon Kim ◽  
Alfi Rodiansyah ◽  
Boklae Cho ◽  
Joonwon Lim ◽  
...  
Keyword(s):  
Electron Beam ◽  
Structural Properties ◽  
Field Emission ◽  
Secondary Electron ◽  
Structural Features ◽  
Cold Cathode ◽  
Sem Images ◽  
Theoretical Simulation ◽  
Field Emission Properties ◽  
Cold Cathodes

Carbon nanotube (CNT)-based cold cathodes are promising sources of field emission electrons for advanced electron devices, particularly for ultra-high-resolution imaging systems, due to their high brightness and low energy spread. While the electron field emission properties of single-tip CNT cathodes have been intensively studied in the last few decades, a systematic study of the influencing factors on the electron beam properties of CNT cold cathodes and the resolution of the secondary electron images has been overlooked in this field. Here, we have systematically investigated the effect of the structural properties of a CNT cold cathode on the electron beam properties and resolution of secondary electron microscope (SEM) images. The aspect ratio (geometric factor) and the diameter of the tip of a vertically standing CNT cold cathode significantly affect the electron beam properties, including the beam size and brightness, and consequently determine the resolution of the secondary electron images obtained by SEM systems equipped with a CNT cold cathode module. Theoretical simulation elucidated the dependence of the structural features of CNT cold cathodes and electron beam properties on the contribution of edge-emitted electrons to the total field emission current. Investigating the correlations between the structural properties of CNT cold cathodes, the properties of the emitted electron beams, and the resolution of the secondary electron images captured by SEM equipped with CNT cold cathode modules is highly important and informative as a basic model.

Fabrication of Groove Shape Cold Cathode for Enhancing Field Emission Properties of Carbon Nanotube

2014 ◽  
Vol 43 (4) ◽  
pp. 423001
Author(s):  
王凤歌 WANG Feng-ge ◽  
李玉魁 LI Yu-kui ◽  
卢文科 LU Wen-ke
Keyword(s):  
Carbon Nanotube ◽  
Field Emission ◽  
Cold Cathode ◽  
Emission Properties ◽  
Field Emission Properties ◽  
Groove Shape

Field Emission Properties of Individual Carbon Nanotubes in Nanorobotic Manipulation and Electron-Beam-Induced Deposition

2004 ◽  
Vol 16 (6) ◽  
pp. 597-603 ◽  
Author(s):  
Fumihito Arai ◽  
◽  
Pou Liu ◽  
Lixin Dong ◽  
Toshio Fukuda ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electron Beam ◽  
Field Emission ◽  
Emission Current ◽  
Emission Properties ◽  
Field Emission Properties ◽  
Field Emission Current ◽  
Multi Walled Carbon Nanotubes ◽  
Electron Beam Induced Deposition ◽  
Afm Cantilever

Field emission properties of individual multi-walled carbon nanotubes (MWNTs) were studied in nanorobotic manipulation and electron-beam-induced deposition (EBID). Nanotube emitters are constructed by picking up and assembling individual nanotubes on a commercially available atomic force microscope (AFM) cantilever or a tungsten probe. The relationship between field emission current and interelectrode distance was obtained by changing the distance between the tip of the nanotube emitter and the counterpart anode, which can be potentially applied as the principle for an approaching sensor to detect nanometer scale distance by observing field emission current in real time. Field emission current on a microampere scale from a CNT emitter was shown to be strong enough for EBID without obviously degrading emitters. Deposit topology was related to current density or the emitter shape, suggesting that information on emitter geometry could be obtained from EBID deposits. Energy dispersive X-ray spectrometry (EDS) analysis of deposits from W(CO)6showed that the tungsten mass exceeds 80% on the average among compositions. Much higher voltage may degrade the emitter, and saturated current may be used to adjust the emitter length in a controlled way.

Layered MoS 2 Nanosheets Fabricated by Vacuum Electron Beam Evaporation and Thickness‐Dependent Field Emission Properties

2019 ◽  
Vol 216 (20) ◽  
pp. 1900180 ◽  
Author(s):  
Mei-Mei Guo ◽  
Xiao-Ping Wang ◽  
Li-Jun Wang ◽  
Xin-Wei Yang ◽  
Ying Yang ◽  
...  
Keyword(s):  
Electron Beam ◽  
Field Emission ◽  
Electron Beam Evaporation ◽  
Emission Properties ◽  
Field Emission Properties ◽  
Dependent Field

Field emission properties of self-assembled silicon nanostructures formed by electron beam annealing

2006 ◽  
Vol 6 (3) ◽  
pp. 503-506 ◽  
Author(s):  
S. Johnson ◽  
A. Markwitz ◽  
M. Rudolphi ◽  
H. Baumann ◽  
S.P. Oei ◽  
...  
Keyword(s):  
Electron Beam ◽  
Field Emission ◽  
Silicon Nanostructures ◽  
Emission Properties ◽  
Field Emission Properties ◽  
Self Assembled

Secondary electron imaging of MoO3 reduction in a UHV STEM

1989 ◽  
Vol 47 ◽  
pp. 86-87
Author(s):  
P. A. Crozier ◽  
J. Liu ◽  
J. M. Cowley
Keyword(s):  
Electron Beam ◽  
Metal Oxides ◽  
Field Emission ◽  
Secondary Electron ◽  
Electron Beams ◽  
Exit Surface ◽  
Electron Imaging ◽  
Drill Holes ◽  
First Time ◽  
Better Than

Recently, a number of people have studied the ability of focussed electron beams to form lines and holes in metal oxides. Many metal oxides decompose when irradiated under the high intensity focussed probes used in field emission STEMS. Initially, many of these oxides reduce to the metal and in some cases it is possible to drill holes in the material. Understanding the nature of the interaction between the electron beam and the sample is important for materials characterisation. These studies may also lead to the development of new electron beam resists and masks. Here we present some preliminary results on the effect of electron irradiation on MoO3 in a field emission UHV STEM. We show, for the first time, secondary electron (SE)images of the entrance and exit surface of the sample after radiation damage has occurred.The experiments described here were performed on the VG HB501S; a dedicated STEM in which vacuums better than 10-10 torr are routinely available in the column.

A field-emission SEM optimized for operation at low beam voltage

1993 ◽  
Vol 51 ◽  
pp. 630-631
Author(s):  
JB Pawley ◽  
J Ximen ◽  
PS-D Lin ◽  
M. Schippert
Keyword(s):  
High Resolution ◽  
Radiation Damage ◽  
Field Emission ◽  
Secondary Electron ◽  
Structural Features ◽  
Objective Lens ◽  
Beam Diameter ◽  
Beam Voltage ◽  
High Resolution Images ◽  
Topographic Imaging

The advantages of operating the SEM at low beam voltage (V0 ) have been recognized for some time. They include: less specimen charging, greater contrast in the fine topographic component of the secondary electron (SE) signal and reduced radiation damage. Although initially it was difficult to obtain high resolution images when using low V0, this limitation can be essentially overcome by employing both a FE source and an immersion objective lens. In an instrument employing both of these features it is possible to produce a beam diameter of about 3 nm @ 1.5 kV. When insulating specimens are viewed under these conditions, the resolution in the image is limited more by the structure of the coating material than by the beam diameter, while on conductors, small structural features produce useful contrast only at low V0.The remaining obstacle to more widespread use of LVSEM for high resolution topographic imaging is the high cost of the equipment.

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