Study the optimum dimensions and operating parameters of Penning ion source

2017 ◽  
Vol 95 (5) ◽  
pp. 457-463 ◽  
Author(s):  
A.G. Helal ◽  
H. El-Khabeary ◽  
S.I. Radwan
Keyword(s):  
Discharge Current ◽  
Ion Beam ◽  
Surface Hardness ◽  
Beam Current ◽  
Discharge Voltage ◽  
Ion Source ◽  
Aperture Diameter ◽  
Argon Gas ◽  
Exit Aperture ◽  
Hollow Anode

In this work, design and construction of a DC cold cathode Penning ion source is described. It consists of cylindrical hollow anode and two movable disc cathodes that are placed symmetrically at two ends of the anode. The electrical discharge and the output ion beam characteristics of the ion source are measured using argon gas. It is found that the optimum dimensions of anode–cathode distance, ion exit aperture diameter, and ion exit aperture – Faraday cup distance are equal to 8, 1.5, and 30 mm, respectively. The ion source efficiency was calculated at discharge current equal to 1.2 mA, different anode–cathode distances and pressures using argon gas. It is found that at anode–cathode distance equal to 8 mm and pressure equal to 7 × 10−4 mmHg, a maximum ion source efficiency equal to 27.1% can be obtained. The surface hardness of molybdenum specimen is measured after exposure to argon ion beam for two hours at pressure equal to 7 × 10−4 mmHg, discharge voltage equal to 3.5 kV, discharge current equal to 0.6 mA, and output ion beam current equal to 165 μA using argon gas. It is found that the surface hardness of molybdenum specimen is decreased by a factor of 24.2%.

Investigation of conical anode – disc cathode ion source

2018 ◽  
Vol 96 (2) ◽  
pp. 194-201
Author(s):  
S. Abdel Samed ◽  
S.I. Radwan ◽  
H. El-Khabeary
Keyword(s):  
Discharge Current ◽  
Theoretical Calculations ◽  
Ion Beam ◽  
Beam Current ◽  
Ion Source ◽  
Experimental Results ◽  
Maximum Output ◽  
Nitrogen Gas ◽  
Beam Characteristics ◽  
Good Agreement

An axial direct-current conical anode – disc cathode ion source has been designed, constructed, and operated. The electrical discharge and the output ion beam characteristics are measured using nitrogen gas. It is found that at the optimum dimensions, pressure equal to 4.5 × 10−5 mm Hg and discharge current equal to 250 μA, a maximum output ion beam current equal to 91 μA can be obtained. A comparison between the experimental results and theoretical calculations of the output ion beam current values at the optimum dimensions and operating parameters for different discharge current of conical anode and disc cathode ion source using nitrogen gas is determined. It is found that a good agreement exists between the experimental results and theoretical calculations.

Alloy surface composition resulting from fabrication, as determined by s.i.m.s. (secondary ion mass spectrometry)

1980 ◽  
Vol 295 (1413) ◽  
pp. 134-135
Keyword(s):  
Secondary Ion Mass Spectrometry ◽  
Surface Composition ◽  
Ion Beam ◽  
Sample Surface ◽  
Beam Current ◽  
Ion Source ◽  
Beam Current Density ◽  
Dynamic Mode ◽  
Static Mode ◽  
Subsequent Performance

In s.i.m.s. the sample surface is ion bombarded and the emitted secondary ions are mass analysed. When used in the static mode with very low primary ion beam current densities (10 -11 A/mm 2 ), the technique analyses the outermost atomic layers with the following advantages (Benninghoven 1973, I975): the structural—chemical nature of the surface may be deduced from the masses of the ejected ionized clusters of atoms; detection of hydrogen and its compounds is possible; sensitivity is extremely high (10 -6 monolayer) for a number of elements. Composition profiles are obtained by increasing the primary beam current density (dynamic mode) or by combining the technique in the static mode with ion beam machining with a separate, more powerful ion source. The application of static s.i.m.s. in metallurgy has been explored by analysing a variety of alloy surfaces after fabrication procedures in relation to surface quality and subsequent performance. In a copper—silver eutectic alloy braze it was found that the composition of the solid surface depended markedly on its pretreatment. Generally there was a surface enrichment of copper relative to silver in melting processes while sawing and polishing enriched the surface in silver

scholarly journals Developing Ultra Small-Scale Radiocarbon Sample Measurement at the University of Tokyo

Radiocarbon ◽  
2010 ◽  
Vol 52 (2) ◽  
pp. 310-318 ◽  
Author(s):  
Yusuke Yokoyama ◽  
Mamito Koizumi ◽  
Hiroyuki Matsuzaki ◽  
Yosuke Miyairi ◽  
Naohiko Ohkouchi
Keyword(s):  
Ion Beam ◽  
Measurement Techniques ◽  
Beam Current ◽  
Ion Source ◽  
Small Samples ◽  
Small Scale ◽  
Target Holder ◽  
Vacuum Line ◽  
The Difference ◽  
Beam Currents

We have developed accelerator mass spectrometry (AMS) measurement techniques for ultra small-size samples ranging from 0.01 to 0.10 mg C with a new type of MC-SNICS ion source system. We can generate 4 times higher ion beam current intensity for ultra-small samples by optimization of graphite position in the target holder with the new ionizer geometry. CO2 gas graphitized in the newly developed vacuum line is pressed to a depth of 1.5 mm from the front of the target holder. This is much deeper than the previous position at 0.35 mm depth. We measured 12C4+ beam currents generated by small standards and ion beam currents (15–30 μA) from the targets in optimized position, lasting 20 min for 0.01 mg C and 65 min for 0.10 mg C. We observed that the measured 14C/12C ratios are unaffected by the difference of ion beam currents ranging from 5 to 30 μA, enabling measurement of ultra-small samples with high precision. Examination of the background samples revealed 1.1 μg of modern and 1 μg of dead carbon contaminations during target graphite preparation. We make corrections for the contamination from both the modern and background components. Reduction of the contamination is necessary for conducting more accurate measurement.

FABRICATION AND MODELING OF MICROCHANNEL MILLING USING FOCUSED ION BEAM

2003 ◽  
Vol 02 (04n05) ◽  
pp. 375-379 ◽  
Author(s):  
A. A. TSENG ◽  
B. LEELADHARAN ◽  
B. LI ◽  
I. INSUA ◽  
C. D. CHEN
Keyword(s):  
Numerical Model ◽  
Silicon Wafer ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Beam Current ◽  
Ion Source ◽  
Experimental Measurements ◽  
Model Predictions

The capability of using Focused Ion Beam (FIB) for milling microchannels is experimentally and theoretically investigated. Microchannel structures are fabricated by a NanoFab 150 FIB machine, using an Arsenic (As2+) ion source. A beam current of 5 pA at 90 keV accelerating energy is used. Several microchannel patternings are milled at various dwell times at pixel spacing of 14.5 nm on top of a 60 nm gold-coated silicon wafer. An analytical/numerical model is developed to predict the FIB milling behavior. By comparing with the experimental measurements, the model predictions have been demonstrated to be reliable for guiding and controlling the milling processes.

Characterization of the Ion Beam Current Density of the RF Ion Source with Flat and Convex Extraction Systems

Silicon ◽  
2018 ◽  
Vol 10 (6) ◽  
pp. 2743-2749 ◽  
Author(s):  
Maryam Salehi ◽  
Ali Asghar Zavarian ◽  
Ali Arman ◽  
Fatemeh Hafezi ◽  
Ghasem Amraee Rad ◽  
...  
Keyword(s):  
Current Density ◽  
Ion Beam ◽  
Beam Current ◽  
Ion Source ◽  
Beam Current Density ◽  
Rf Ion Source

scholarly journals Direct Write of 3D Nanoscale Mesh Objects with Platinum Precursor via Focused Helium Ion Beam Induced Deposition

Micromachines ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 527
Author(s):  
Alex Belianinov ◽  
Matthew J. Burch ◽  
Anton Ievlev ◽  
Songkil Kim ◽  
Michael G. Stanford ◽  
...  
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Beam Current ◽  
Ion Source ◽  
Direct Write ◽  
Gas Field ◽  
Critical Dimensions ◽  
3D Mesh ◽  
Nanoscale Structures ◽  
Helium Ion

The next generation optical, electronic, biological, and sensing devices as well as platforms will inevitably extend their architecture into the 3rd dimension to enhance functionality. In focused ion beam induced deposition (FIBID), a helium gas field ion source can be used with an organometallic precursor gas to fabricate nanoscale structures in 3D with high-precision and smaller critical dimensions than focused electron beam induced deposition (FEBID), traditional liquid metal source FIBID, or other additive manufacturing technology. In this work, we report the effect of beam current, dwell time, and pixel pitch on the resultant segment and angle growth for nanoscale 3D mesh objects. We note subtle beam heating effects, which impact the segment angle and the feature size. Additionally, we investigate the competition of material deposition and sputtering during the 3D FIBID process, with helium ion microscopy experiments and Monte Carlo simulations. Our results show complex 3D mesh structures measuring ~300 nm in the largest dimension, with individual features as small as 16 nm at full width half maximum (FWHM). These assemblies can be completed in minutes, with the underlying fabrication technology compatible with existing lithographic techniques, suggesting a higher-throughput pathway to integrating FIBID with established nanofabrication techniques.

Electrical Properties of Ultra Shallow p Junction on n type Si Wafer Using Decaborane Ion Implantation

2001 ◽  
Vol 686 ◽  
Author(s):  
Jae-Hoon Song ◽  
Duck-Kyun Choi ◽  
Min-Seok Oh ◽  
Won-Kook Choi
Keyword(s):  
Electrical Properties ◽  
Ion Beam ◽  
Beam Current ◽  
Ion Source ◽  
Low Energy ◽  
Boron Ions ◽  
Boron Dopant ◽  
P Type ◽  
Dopant Source ◽  
Si Wafer

AbstractThe junction depth should be less than 0.05 microns to fabricate sub 0.1 micron devices. This requires implanting boron with energy of less than 1 keV. One drawback in a low energy ion source is low throughput due to low ion beam current. At present, boron known for a major p-type dopant for PMOSFET has problem to easily diffuse into Si wafer even in rapid thermal processing by high diffusivity. To resolve this problem, decaborane (B10H14) molecules are implanted to make p+/n junction on n-type Si wafers for low-energy boron dopant source. Ionized decaborane is accelerated at 1∼10 kV and implanted up to dosages from 1×1012/cm2 to 5×1013/cm2. Afterwards, Decaborane implanted Si wafers were post-annealed for 10 sec at 800, 900 and 1000°C, respectively. From RBS results on as-implanted n-type Si wafer implanted at 5 kV, it is observed there are amorphous Si layers with 4 nm in depth and boron ions are implanted up to 1∼5 nm in depth from SIMS analysis. The electrical properties of these p-n junctions are 127∼130 ω/sq. as sheet resistance, +0.3 V turn-on voltage and −1.1 V breakdown voltage obtained from I-V measurement.

Fusion cross-section measurements with deuterons of low energy

1961 ◽  
Vol 264 (1319) ◽  
pp. 445-457 ◽  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Ion Beam ◽  
Large Angle ◽  
Fusion Cross Section ◽  
Reaction Norm ◽  
Beam Current ◽  
Ion Source ◽  
Target Chamber ◽  
The Cross

A knowledge of the energy dependence of the cross-section for collisions between two deutrons leading to a triton and a proton, is of interest both to nuclear theory and to calculations of the rate of thermonuclear reactions. Until now reliable values were only available down to about 13 keV and thus the contributions by the large number of slower particles in a distribution could not be assessed. The purpose of the work was to extend this range to lower energies which involves the measurement of very small cross-sections. The method of measuring the fusion cross-sections made use of an intense ion beam and of th e observation of the fast protons from the reaction norm al to the beam over an angle 2 π . The beam intensity was raised by avoiding an ion focusing system and using a simple extraction electrode with equal gas pressure in the ion source and gas target. Observation over a large angle was achieved by depositing a scintillation detector on a light guide which surrounded the target chamber. From calorimetric measurements of the beam current and measurements of the counting rate, relative cross-sections were obtained for deuteron energies up to 15 keV where absolute cross-sections are well known. In this w ay absolute values of the cross-section were found from 15 keV down to 4 keV, where a value of 9 x 10 -33 cm 2 was measured. Although the results are consistent with Gamow’s relation, the cross-section in the lower energy range is slightly larger than expected.

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