Nanoscale Manipulation for The Fabrication of Field-emission Air-channel Transistors

Field emission air-channel (FEAC) devices can work under atmospheric pressure with a low operation voltage when the electron channel is far less than the mean free path (MFP) in the air, thereby making them a practical component in circuits. Forward and reverse electron emissions of the current FEAC devices demonstrated symmetric Fowler–Nordheim (F–N) plots owing to the symmetric cathode and anode electrodes. This research aimed to demonstrate the arithmetic application of the FEAC devices, their substrate effect, and reliability. A voltage adder was composed of two FEAC devices whose two inputs were connected to two separate function generators, and one output was wire-connected to an oscilloscope. The devices were on a thin dielectric film and low-resistivity silicon substrate to evaluate the parasitic components and substrate effect, resulting in frequency-dependent impedance. The results show that the FEAC devices possessed arithmetic function, but the output voltage decreased. The FEAC devices were still capable of serving as a voltage adder after the reliability test, but electric current leakage increased. Finite element analysis indicated that the highest electrical fields and electron trajectories occur at the apices where the electrons travel with the shortest route less than the MFP in the air, thereby meeting the FEAC devices’ design. The modeling also showed that a sharp apex would generate a high electric field at the tip-gap-tip, enhancing the tunneling current.

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Semiconductor-Free Field-Emission Nanoelectronics: Application in Air-Channel Transistors

2019 International Vacuum Electronics Conference (IVEC) ◽

10.1109/ivec.2019.8745106 ◽

2019 ◽

Cited By ~ 1

Author(s):

Shruti Nirantar ◽

Taimur Ahmed ◽

Guanghui Ren ◽

Philipp Gutruf ◽

Chengong Xu ◽

...

Keyword(s):

Field Emission ◽

Free Field ◽

Air Channel

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Metal–Air Transistors: Semiconductor-Free Field-Emission Air-Channel Nanoelectronics

Nano Letters ◽

10.1021/acs.nanolett.8b02849 ◽

2018 ◽

Vol 18 (12) ◽

pp. 7478-7484 ◽

Cited By ~ 22

Author(s):

Shruti Nirantar ◽

Taimur Ahmed ◽

Guanghui Ren ◽

Philipp Gutruf ◽

Chenglong Xu ◽

...

Keyword(s):

Field Emission ◽

Free Field ◽

Air Channel

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Observation of Phase Contrast Images in STEM and CTEM Modes by Using 100 kV Field Emission Electron Gun

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100051967 ◽

1974 ◽

Vol 32 ◽

pp. 390-391

Author(s):

Y. Harada ◽

T. Goto ◽

H. Koike ◽

T. Someya

Keyword(s):

Field Emission ◽

Phase Contrast ◽

Image Formation ◽

Fresnel Diffraction ◽

Experimental Results ◽

Electron Gun ◽

Scanning Microscopy ◽

Emission Electron ◽

Lattice Images

Since phase contrasts of STEM images, that is, Fresnel diffraction fringes or lattice images, manifest themselves in field emission scanning microscopy, the mechanism for image formation in the STEM mode has been investigated and compared with that in CTEM mode, resulting in the theory of reciprocity. It reveals that contrast in STEM images exhibits the same properties as contrast in CTEM images. However, it appears that the validity of the reciprocity theory, especially on the details of phase contrast, has not yet been fully proven by the experiments. In this work, we shall investigate the phase contrast images obtained in both the STEM and CTEM modes of a field emission microscope (100kV), and evaluate the validity of the reciprocity theory by comparing the experimental results.

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A New Image Processing Technique for STEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100052171 ◽

1974 ◽

Vol 32 ◽

pp. 432-433

Author(s):

Yasushi Kokubo ◽

Hirotami Koike ◽

Teruo Someya

Keyword(s):

Electron Microscopy ◽

Image Processing ◽

Scanning Electron Microscopy ◽

Elastic Scattering ◽

Field Emission ◽

Processing Technique ◽

Image Processing Technique ◽

Energy Analyzer ◽

Scanning Microscope ◽

Scanning Electron

One of the advantages of scanning electron microscopy is the capability for processing the image contrast, i.e., the image processing technique. Crewe et al were the first to apply this technique to a field emission scanning microscope and show images of individual atoms. They obtained a contrast which depended exclusively on the atomic numbers of specimen elements (Zcontrast), by displaying the images treated with the intensity ratio of elastically scattered to inelastically scattered electrons. The elastic scattering electrons were extracted by a solid detector and inelastic scattering electrons by an energy analyzer. We noted, however, that there is a possibility of the same contrast being obtained only by using an annular-type solid detector consisting of multiple concentric detector elements.

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Observation of Atom Rows in Thorium Pyromellitate Using a Field Emission STEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010007802x ◽

1977 ◽

Vol 35 ◽

pp. 80-81

Author(s):

H. Todokoro ◽

S. Nomura ◽

T. Komoda

Keyword(s):

Field Emission ◽

Amorphous Carbon ◽

Carbon Film ◽

Dark Field Image ◽

Dark Field ◽

Amorphous Carbon Film ◽

Atomic Size ◽

Wide Range ◽

A Chain

It is interesting to observe polymers at atomic size resolution. Some works have been reported for thorium pyromellitate by using a STEM (1), or a CTEM (2,3). The results showed that this polymer forms a chain in which thorium atoms are arranged. However, the distance between adjacent thorium atoms varies over a wide range (0.4-1.3nm) according to the different authors.The present authors have also observed thorium pyromellitate specimens by means of a field emission STEM, described in reference 4. The specimen was prepared by placing a drop of thorium pyromellitate in 10-3 CH3OH solution onto an amorphous carbon film about 2nm thick. The dark field image is shown in Fig. 1A. Thorium atoms are clearly observed as regular atom rows having a spacing of 0.85nm. This lattice gradually deteriorated by successive observations. The image changed to granular structures, as shown in Fig. 1B, which was taken after four scanning frames.

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A Stable Field Emission Electron Source

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100077918 ◽

1977 ◽

Vol 35 ◽

pp. 58-59

Author(s):

W.R. Bottoms ◽

G.B. Haydon

Keyword(s):

Field Emission ◽

Signal To Noise Ratio ◽

High Brightness ◽

Electron Sources ◽

Brightness Field ◽

Current Densities ◽

Properties Of Materials ◽

Stable Field ◽

Stable Current ◽

Careful Design

There is great interest in improving the brightness of electron sources and therefore the ability of electron optical instrumentation to probe the properties of materials. Extensive work by Dr. Crew and others has provided extremely high brightness sources for certain kinds of analytical problems but which pose serious difficulties in other problems. These sources cannot survive in conventional system vacuums. If one wishes to gather information from the other signal channels activated by electron beam bombardment it is necessary to provide sufficient current to allow an acceptable signal-to-noise ratio. It is possible through careful design to provide a high brightness field emission source which has the capability of providing high currents as well as high current densities to a specimen. In this paper we describe an electrode to provide long-lived stable current in field emission sources.The source geometry was based upon the results of extensive computer modeling. The design attempted to maximize the total current available at a specimen.

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Field Emission SEM Equipped With Noise Compensator

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100071958 ◽

1973 ◽

Vol 31 ◽

pp. 302-303

Author(s):

S. Saito ◽

H. Todokoro ◽

S. Nomura ◽

T. Komoda

Keyword(s):

Electron Microscope ◽

High Resolution ◽

Scanning Electron Microscope ◽

Field Emission ◽

Low Contrast ◽

Probe Current ◽

High Resolution Images ◽

Scanning Electron

Field emission scanning electron microscope (FESEM) features extremely high resolution images, and offers many valuable information. But, for a specimen which gives low contrast images, lateral stripes appear in images. These stripes are resulted from signal fluctuations caused by probe current noises. In order to obtain good images without stripes, the fluctuations should be less than 1%, especially for low contrast images. For this purpose, the authors realized a noise compensator, and applied this to the FESEM.Fig. 1 shows an outline of FESEM equipped with a noise compensator. Two apertures are provided gust under the field emission gun.

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A Field Emission System For Transmission Electron Microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100071934 ◽

1973 ◽

Vol 31 ◽

pp. 298-299

Author(s):

Michel Troyonal ◽

Huei Pei Kuoal ◽

Benjamin M. Siegelal

Keyword(s):

Electron Microscope ◽

Field Emission ◽

Optical System ◽

High Vacuum ◽

Ultra High Vacuum ◽

Objective Lens ◽

Electron Optical System ◽

Cross Sectional ◽

Transmission Electron ◽

Emission System

A field emission system for our experimental ultra high vacuum electron microscope has been designed, constructed and tested. The electron optical system is based on the prototype whose performance has already been reported. A cross-sectional schematic illustrating the field emission source, preaccelerator lens and accelerator is given in Fig. 1. This field emission system is designed to be used with an electron microscope operated at 100-150kV in the conventional transmission mode. The electron optical system used to control the imaging of the field emission beam on the specimen consists of a weak condenser lens and the pre-field of a strong objective lens. The pre-accelerator lens is an einzel lens and is operated together with the accelerator in the constant angular magnification mode (CAM).

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