scholarly journals Analysis of field-emission from a diamond-metal-vacuum triple junction

2012 ◽  
Vol 112 (6) ◽  
pp. 066102 ◽  
Author(s):  
S. Sun ◽  
L. K. Ang
Author(s):  
Moon S. Chung ◽  
Hae K. Bae ◽  
A. Mayer ◽  
Paul H. Cutler ◽  
Nicholas M. Miskovsky

2001 ◽  
Vol 692 ◽  
Author(s):  
Namwoong Paik ◽  
Michael Martin ◽  
Daeil Kim ◽  
Sungjin Kim ◽  
Steven Kim ◽  
...  

AbstractNegative Electron Affinity (NEA) of Diamond-like-Carbon (DLC) films has made DLC films a favorable candidate for field emission display (FED). It was suggested that triple-junction type structure could enhance the field emission characteristics. A triple junction is defined as the intersection of a semiconductor surface with a metal substrate in vacuum. In this study, field emission enhancement in triple junction type structures was investigated. As a metal substrate 5000 of Mo films were deposited. Then, 3000–4000 of DLC film was deposited as a semiconductor material. Thin film layers were made using a negative ion beam source. After the deposition, using an excimer laser, we removed the DLC layer and made circular shaped triple junction trenches with a diameter of 25–250 μm. The field emission characteristics such as I–V characteristics turn on voltage and emission lifetime data were obtained for a diode type field emission measurement system. Overall results show significantly enhanced performance of field emission characteristics such as uniform emission over patterned area, reduced turn on voltages and longer lifetimes can be achieved.


Author(s):  
M. S. Chung ◽  
H. K. Bae ◽  
Y. J. Jang ◽  
P. H. Cutler ◽  
N. M. Miskovsky

Author(s):  
Y. Harada ◽  
T. Goto ◽  
H. Koike ◽  
T. Someya

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.


Author(s):  
Yasushi Kokubo ◽  
Hirotami Koike ◽  
Teruo Someya

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.


Author(s):  
H. Todokoro ◽  
S. Nomura ◽  
T. Komoda

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.


Author(s):  
W.R. Bottoms ◽  
G.B. Haydon

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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