Effects of Beam Current Density on Ion Beam Synthesis OF SiC

2001 ◽  
Vol 680 ◽  
Author(s):  
D.H. Chen ◽  
S.P. Wong ◽  
J.K.N. Lindner
Keyword(s):  
Current Density ◽  
Photoelectron Spectroscopy ◽  
Ion Beam ◽  
Metal Vapor ◽  
Beam Current ◽  
Ion Source ◽  
Vacuum Arc ◽  
Beam Current Density ◽  
Carbon Clusters ◽  
High Dose

ABSTRACTThin SiC layers were synthesized by high dose C implantation into silicon using a metal vapor vacuum arc ion source at various conditions. Characterization of the ion beam synthesized SiC layers was performed using various techniques including x-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) absorption, and Raman spectroscopy. The XPS results showed that for samples with over-stoichiometric implant doses, if the implant beam current density was not high enough, even after prolonged thermal annealing at high temperatures, the as-implanted gaussian-like carbon depth profile remained unchanged. However, if the implant beam current density was sufficiently high, there was significant carbon redistribution during annealing, so that a thicker stoichiometric SiC layer can be formed after annealing. The XPS and Raman results also showed that there were carbon clusters formed in the as-implanted layers for the low beam current density implanted samples, while the formation of such carbon clusters was minimal in the high beam current density as-implanted samples. The effect of beam current density on the fraction of different bonding states of the implanted carbon atoms was studied.

Field Emission Properties of Ion Beam Synthesized SiC/Si Heterostructures by MEVVA Implantation

1998 ◽  
Vol 509 ◽  
Author(s):  
Dihu Chen ◽  
S. P. Wong ◽  
W.Y. Cheung ◽  
E.Z. Luo ◽  
W. Wu ◽  
...  
Keyword(s):  
Field Emission ◽  
Photoelectron Spectroscopy ◽  
Ion Beam ◽  
Metal Vapor ◽  
Ion Source ◽  
Vacuum Arc ◽  
High Dose ◽  
Emission Properties ◽  
Field Emission Properties ◽  
Two Factors

AbstractPlanar SiC/Si heterostructures were formed by high dose carbon implantation using a metal vapor vacuum arc ion source. The variations of the field emission properties with the implant dose and annealing conditions were studied. A remarkably low turn-on field of IV/μm was observed from a sample implanted at 35 keV to a dose of 1.0×1018 cm−2 with subsequent annealing in nitrogen at 1200°C for 2h. The chemical composition depth profiles were determined from x-ray photoelectron spectroscopy and the surface morphology was observed by atomic force microscopy. The formation of a thin surface stoichiometric SiC layer and the formation of densely distributed small protrusions on the surface are believed to be the two factors responsible for the efficient electron field emission.

Magnetoresistance Effects in Granular Thin Layers Formed by High Dose Iron Implantation Into Silicon

1997 ◽  
Vol 475 ◽  
Author(s):  
S.P. Wong ◽  
W.Y. Cheung
Keyword(s):  
Magnetic Field ◽  
Current Density ◽  
Beam Current ◽  
Implantation Dose ◽  
Ion Source ◽  
Thin Layers ◽  
Beam Current Density ◽  
High Dose ◽  
Zero Field ◽  
Mr Effect

ABSTRACTHigh dose iron implantation into silicon substrates has been performed with a metal vapor vacuum arc ion source to doses ranging from 5×1016 to 2×1017 cm'2 at various beam current densities. The magnetoresistance (MR) effects in these implanted granular layers were studied at temperatures from 15K to 300K. A positive MR effect, i.e., an increase in the resistance at the presence of a magnetic field, was observed at temperatures lower than about 40K in samples prepared under appropriate implantation conditions. The magnitude of the MR effect, defined as ΔR/Ro ≡ (R(H)-Ro)/Ro where R(H) and Ro denote respectively the resistance value at a magnetic field intensity H and that at zero field, was found to depend not only on the implantation dose but also on the beam current density. This is attributed to the beam heating effect during implantation which affects the formation of the microstructures. The ratio δR/Ro was found to attain high values larger than 400% for some samples at low temperatures. The dependence of the MR effects on temperature, implantation dose, and beam current density will be presented and discussed in conjunction with results of transmission electron microscopy.

Effects of Dwell Time and Current Density on Ion-Induced Deposition of Tungsten

1990 ◽  
Vol 181 ◽  
Author(s):  
Khanh Q. Tran ◽  
Yuuichi Madokoro ◽  
Tohru Ishitani ◽  
Cary Y. Yang
Keyword(s):  
Current Density ◽  
Dwell Time ◽  
Ion Beam ◽  
Dose Range ◽  
Beam Current ◽  
Beam Current Density ◽  
High Dose ◽  
Beam Diameter ◽  
Film Resistivity ◽  
Deposition Yield

ABSTRACT30-keV focused Ga+ ion beam was used for induced deposition of small-area tungsten thin films from W(CO)6 on Si and SiO2. Deposition yield, calculated assuming pure tungsten depositions, depends on dwell time (beam diameter/scan speed) and beam current density. High current density and/or long dwell time are known to cause low deposition yield because of the depletion of adsorbed gas molecules during ion beam irradiation. Based on a model taking this effect into account, numerical fitting was carried out. The reaction cross-section was estimated to be 1.4 × 10−14 cm2. For doses below 1017 ions/cm2, film resistivity decreases with increasing dose. This was confirmed for several dwell times. However, for doses above 1017 ions/cm2, film resistivity remains independent of dose. In this “high”-dose range, variation of beam current density has little effect on film resistivity. AES analyses revealed a consistency between film composition and resistivity. For a “high”-dose film with a resistivity of 190 μΩ-cm, the approximate tungsten content was 50 at%.

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

Beam current density distribution of a vacuum arc ion source

1998 ◽  
Vol 69 (2) ◽  
pp. 807-809 ◽  
Author(s):  
A. G. Nikolaev ◽  
E. M. Oks ◽  
Xiaoji Zhang ◽  
Cheng Cheng
Keyword(s):  
Density Distribution ◽  
Current Density ◽  
Current Density Distribution ◽  
Beam Current ◽  
Ion Source ◽  
Vacuum Arc ◽  
Beam Current Density

scholarly journals Space-charge compensation of highly charged ion beam from laser ion source

1996 ◽  
Vol 14 (3) ◽  
pp. 323-333 ◽  
Author(s):  
S.A. Kondrashev ◽  
J. Collier† ◽  
T. R. Sherwood†
Keyword(s):  
Space Charge ◽  
Current Density ◽  
Ion Beam ◽  
Charge Compensation ◽  
Beam Current ◽  
Ion Source ◽  
Beam Current Density ◽  
Laser Ion Source ◽  
Beam Transport ◽  
Highly Charged Ion

The problem of matching an ion beam delivered by a high-intensity ion source with an accelerator is considered. The experimental results of highly charged ion beam transport with space-charge compensation by electrons are presented. A tungsten thermionic cathode is used as a source of electrons for beam compensation. An increase of ion beam current density by a factor of 25 is obtained as a result of space-charge compensation at a distance of 3 m from the extraction system. The process of ion beam space-charge compensation, requirements for a source of electrons, and the influence of recombination losses in a spacecharge-compensated ion beam are discussed.

Growth and Characterization of Erbium Silicides Synthesized by Metal Vapor Vacuum Arc Ion Implantation

2000 ◽  
Vol 647 ◽  
Author(s):  
X. W. Zhang ◽  
W. Y. Cheung ◽  
S. P. Wong
Keyword(s):  
Rutherford Backscattering Spectrometry ◽  
Metal Vapor ◽  
Beam Current ◽  
Ion Source ◽  
Vacuum Arc ◽  
Beam Current Density ◽  
Metal Vapour ◽  
Sputtering Yield ◽  
Substrate Temperatures

AbstractErbium atoms were implanted into p-type Si (111) wafers at an extraction voltage of 60 kV to doses ranging from 5×1016 to 2×1017 cm−2 using a metal vapour vacuum arc (MEVVA) ion source. The implantation was performed with beam current densities from 3 to 26 µA/cm2 corresponding to substrate temperatures ranging from 85 to 245°C. The characterization of the as-implanted and annealed samples was performed using Rutherford backscattering spectrometry, atomic force microscopy and x-ray diffraction. To determine the sputtering yield, masked implantation experiments were performed so that the thickness of the sputtered layer at different substrate temperatures can be obtained directly by an α-step surface profiler. The results showed that ErSi2-xwas directly formed by MEVVA implantation when the substrate temperature was higher than about 160°C. The effects of the implant dose and the beam current density on the retained dose, the sputtering yield and the surface morphology of the implanted samples were also studied.

Effects of a dielectric material in an ion source on the ion beam current density and ion beam energy

2016 ◽  
Vol 87 (2) ◽  
pp. 02B930
Author(s):  
Y. Fujiwara ◽  
H. Sakakita ◽  
A. Nakamiya ◽  
Y. Hirano ◽  
S. Kiyama
Keyword(s):  
Current Density ◽  
Beam Energy ◽  
Dielectric Material ◽  
Ion Beam ◽  
Beam Current ◽  
Ion Source ◽  
Beam Current Density

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 Formation of Buried Epitaxial Si-Ge Alloy Layers in Si Crystal by High Dose Ge ION Implantation

1991 ◽  
Vol 235 ◽  
Author(s):  
Kin Man Yu ◽  
Ian G. Brown ◽  
Seongil Im
Keyword(s):  
Ion Implantation ◽  
Single Crystal ◽  
Lattice Mismatch ◽  
Solid Phase ◽  
Metal Vapor ◽  
Ion Source ◽  
Vacuum Arc ◽  
High Dose ◽  
Solid Phase Epitaxy ◽  
Ion Channeling

ABSTRACTWe have synthesized single crystal Si1−xGex alloy layers in Si <100> crystals by high dose Ge ion implantation and solid phase epitaxy. The implantation was performed using the metal vapor vacuum arc (Mevva) ion source. Ge ions at mean energies of 70 and 100 keV and with doses ranging from 1×1016 to to 7×1016 ions/cm2 were implanted into Si <100> crystals at room temperature, resulting in the formation of Si1−xGex alloy layers with peak Ge concentrations of 4 to 13 atomic %. Epitaxial regrowth of the amorphous layers was initiated by thermal annealing at temperatures higher than 500°C. The solid phase epitaxy process, the crystal quality, microstructures, interface morphology and defect structures were characterized by ion channeling and transmission electron microscopy. Compositionally graded single crystal Si1−xGex layers with full width at half maximum ∼100nm were formed under a ∼30nm Si layer after annealing at 600°C for 15 min. A high density of defects was found in the layers as well as in the substrate Si just below the original amorphous/crystalline interface. The concentration of these defects was significantly reduced after annealing at 900°C. The kinetics of the regrowth process, the crystalline quality of the alloy layers, the annealing characteristics of the defects, and the strains due to the lattice mismatch between the alloy and the substrate are discussed.

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