Comparison Between Experimental and Simulation Results for Ion Beam and Neutron Irradiations in Silicon Bipolar Junction Transistors

This article describes the simulation results of an astable multivibrator aimed to be fed by a photovoltaic cell, with the purpose of energy harvesting for electronic systems. The circuit was simulated using metal-oxide semiconductor field effect transistors (MOSFETs) and bipolar junction transistors. The use of half-wave and full-wave rectifiers for DC output voltage supply was also analyzed. The circuit reached a peak efficiency of 28 % when using MOSFETs PMDXB550UNE and half wave rectifier.

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Simulation of discharge process of Hall thruster under the internal and external cathode conditions

The European Physical Journal Applied Physics ◽

10.1051/epjap/2020190357 ◽

2020 ◽

Vol 90 (1) ◽

pp. 10801

Author(s):

Xifeng Cao ◽

Hui Liu ◽

Daren Yu

Keyword(s):

Virtual Cathode ◽

High Reliability ◽

Ion Beam ◽

Hall Thruster ◽

Main Beam ◽

Electron Trajectory ◽

Discharge Process ◽

Ion Density ◽

Plume Region ◽

Simulation Results

Hall thruster has been used widely in orbit correction and station-keeping of geostationary satellites for the advantage of high specific impulse, long life, and high reliability. The cathode is an important part of Hall thruster, which can neutralize ion beam and provide electrons to the thruster for ionization. At present, the position of cathode can be divided into two kinds: internal cathode and external cathode. And the discharge parameters under the two different cathode positions is very different, such as the coupling voltage and the ion density. And this paper considers the mechanism of influence of the cathode position on the discharge process of Hall thruster, the discharge process of Hall thruster under internal and external cathode conditions was simulated by PIC-MCC simulation method. The simulation results show that the electron conduction near the thruster outlet is relatively strong under the internal cathode condition. The trajectory of electrons emitted from the cathode position under the two conditions is further simulated. The simulation results show that the electrons will be bound by the magnetic field and form a virtual cathode when they enter the simulation area. The lower coupling voltage under the internal cathode condition is explained by comparing the positions of virtual cathode. At the same time, some electrons emitted from the internal cathode position can quickly reach the main beam region. The ion density distribution is also compared. The ionization regions of Xe+, Xe2+ and Xe3+ ions are relatively outside under the internal cathode condition, and the peak densities of Xe2+ and Xe3+ ions are relatively low. Compared with the experimental results, it is shown that the electron trajectory in the plume region has a significant effect on the plume shape.

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Simulator for Dynamic Ion Beam Mixing

MRS Proceedings ◽

10.1557/proc-279-29 ◽

1992 ◽

Vol 279 ◽

Cited By ~ 1

Author(s):

A. Seidl ◽

K. Fujii ◽

M. Kiuchi ◽

M. Satou ◽

M. Takai

Keyword(s):

Reasonable Agreement ◽

Ion Beam ◽

Layer Growth ◽

Beam Irradiation ◽

Ion Beam Irradiation ◽

Time Step ◽

Ion Beam Mixing ◽

Simulation Results ◽

Time Standard ◽

First Time

ABSTRACTDynamic ion beam mixing (simultaneous deposition and ion beam irradiation) was simulated for the first time. Standard Monte Carlo (MC) programs do not account for the steady change of target geometry caused by the layer growth during the process. Therefore a time-step strategy was realized by integrating a MC simulator in a system together with a geometry update module. A comparison between simulation results and XPS and TEM measurements shows reasonable agreement between simulation and measurements.

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Development of astable multivibrators powered by photovoltaic cells

10.36227/techrxiv.12006048.v1 ◽

2020 ◽

Author(s):

Antonio Telles

Keyword(s):

Field Effect ◽

Output Voltage ◽

Field Effect Transistors ◽

Photovoltaic Cells ◽

Bipolar Junction Transistors ◽

Peak Efficiency ◽

Full Wave ◽

Half Wave ◽

Astable Multivibrator ◽

Simulation Results

This article describes the simulation results of an astable multivibrator aimed to be fed by a photovoltaic cell, with the purpose of energy harvesting for electronic systems. The circuit was simulated using metal-oxide semiconductor field effect transistors (MOSFETs) and bipolar junction transistors. The use of half-wave and full-wave rectifiers for DC output voltage supply was also analyzed. The circuit reached a peak efficiency of 28 % when using MOSFETs PMDXB550UNE and half wave rectifier.

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Direct Observations of the Epitaxial Growth of Sputtered Ag on Si

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100071053 ◽

1973 ◽

Vol 31 ◽

pp. 122-123

Author(s):

J. S. Maa ◽

Thos. E. Hutchinson

Keyword(s):

Epitaxial Growth ◽

Film Growth ◽

Ion Beam ◽

Ion Beam Sputtering ◽

Microscopy Technique ◽

Direct Observations ◽

In Situ Electron Microscopy ◽

Beam Sputtering ◽

The Subject

The growth of Ag films deposited on various substrate materials such as MoS2, mica, graphite, and MgO has been investigated extensively using the in situ electron microscopy technique. The three stages of film growth, namely, the nucleation, growth of islands followed by liquid-like coalescence have been observed in both the vacuum vapor deposited and ion beam sputtered thin films. The mechanisms of nucleation and growth of silver films formed by ion beam sputtering on the (111) plane of silicon comprise the subject of this paper. A novel mode of epitaxial growth is observed to that seen previously.The experimental arrangement for the present study is the same as previous experiments, and the preparation procedure for obtaining thin silicon substrate is presented in a separate paper.

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Effects of Ion Beam Milling on Surface Topography

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100070862 ◽

1973 ◽

Vol 31 ◽

pp. 84-85

Author(s):

P.G. Pawar ◽

P. Duhamel ◽

G.W. Monk

Keyword(s):

Surface Topography ◽

Ion Beam ◽

Solid Material ◽

Beam Current ◽

Atomic Mass ◽

Micro Milling ◽

Ion Milling ◽

Controlled Atmospheres ◽

Milling Operations ◽

Sufficient Energy

A beam of ions of mass greater than a few atomic mass units and with sufficient energy can remove atoms from the surface of a solid material at a useful rate. A system used to achieve this purpose under controlled atmospheres is called an ion miliing machine. An ion milling apparatus presently available as IMMI-III with a IMMIAC was used in this investigation. Unless otherwise stated, all the micro milling operations were done with Ar+ at 6kv using a beam current of 100 μA for each of the two guns, with a specimen tilt of 15° from the horizontal plane.It is fairly well established that ion bombardment of the surface of homogeneous materials can produce surface topography which resembles geological erosional features.

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Nucleation and Early Growth of Sputtered thin Films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100069570 ◽

1970 ◽

Vol 28 ◽

pp. 516-517

Author(s):

Dudley M. Sherman ◽

Thos. E. Hutchinson

Keyword(s):

Thin Films ◽

Electron Beam ◽

Ion Beam ◽

Ion Source ◽

Water Cooling ◽

Stages Of Growth ◽

Lens Assembly ◽

Microscope Technique ◽

Ion Beam Sputter Deposition

The in situ electron microscope technique has been shown to be a powerful method for investigating the nucleation and growth of thin films formed by vacuum vapor deposition. The nucleation and early stages of growth of metal deposits formed by ion beam sputter-deposition are now being studied by the in situ technique.A duoplasmatron ion source and lens assembly has been attached to one side of the universal chamber of an RCA EMU-4 microscope and a sputtering target inserted into the chamber from the opposite side. The material to be deposited, in disc form, is bonded to the end of an electrically isolated copper rod that has provisions for target water cooling. The ion beam is normal to the microscope electron beam and the target is placed adjacent to the electron beam above the specimen hot stage, as shown in Figure 1.

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SEM analysis of DC magnetron sputtered beryllium films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100106867 ◽

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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Ion Beam Induced Interfacial Reactions in Molybdenum Thin Films on Silicon

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100097466 ◽

1981 ◽

Vol 39 ◽

pp. 162-163

Author(s):

L. J. Chen ◽

L. S. Hung ◽

J. W. Mayer

Keyword(s):

Ion Beam ◽

Chemical Vapor ◽

Interfacial Reactions ◽

Practical Applications ◽

Microelectronic Devices ◽

Recent Emergence ◽

Chemical Vapor Deposited ◽

Atomic Mixing ◽

Silicon Interface ◽

Kinetics Of

When an energetic ion penetrates through an interface between a thin film (of species A) and a substrate (of species B), ion induced atomic mixing may result in an intermixed region (which contains A and B) near the interface. Most ion beam mixing experiments have been directed toward metal-silicon systems, silicide phases are generally obtained, and they are the same as those formed by thermal treatment.Recent emergence of silicide compound as contact material in silicon microelectronic devices is mainly due to the superiority of the silicide-silicon interface in terms of uniformity and thermal stability. It is of great interest to understand the kinetics of the interfacial reactions to provide insights into the nature of ion beam-solid interactions as well as to explore its practical applications in device technology.About 500 Å thick molybdenum was chemical vapor deposited in hydrogen ambient on (001) n-type silicon wafer with substrate temperature maintained at 650-700°C. Samples were supplied by D. M. Brown of General Electric Research & Development Laboratory, Schenectady, NY.

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