An ion source with good beam current density uniformity for assisted deposition

1994 ◽  
Vol 65 (4) ◽  
pp. 1374-1376
Author(s):  
Kuang Yuan‐Zhu ◽  
Feng Yu‐Cai ◽  
Lou Zhi‐Ping
1997 ◽  
Vol 475 ◽  
Author(s):  
S.P. Wong ◽  
W.Y. Cheung

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.


Silicon ◽  
2018 ◽  
Vol 10 (6) ◽  
pp. 2743-2749 ◽  
Author(s):  
Maryam Salehi ◽  
Ali Asghar Zavarian ◽  
Ali Arman ◽  
Fatemeh Hafezi ◽  
Ghasem Amraee Rad ◽  
...  

2001 ◽  
Vol 680 ◽  
Author(s):  
D.H. Chen ◽  
S.P. Wong ◽  
J.K.N. Lindner

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.


1998 ◽  
Vol 69 (2) ◽  
pp. 807-809 ◽  
Author(s):  
A. G. Nikolaev ◽  
E. M. Oks ◽  
Xiaoji Zhang ◽  
Cheng Cheng

1996 ◽  
Vol 14 (3) ◽  
pp. 323-333 ◽  
Author(s):  
S.A. Kondrashev ◽  
J. Collier† ◽  
T. R. Sherwood†

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.


2016 ◽  
Vol 87 (2) ◽  
pp. 02B930
Author(s):  
Y. Fujiwara ◽  
H. Sakakita ◽  
A. Nakamiya ◽  
Y. Hirano ◽  
S. Kiyama

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


2009 ◽  
Vol 17 (3) ◽  
pp. 30-35
Author(s):  
S.D. Walck ◽  
J.R. Porter ◽  
H-W. Yang ◽  
S.S. Dheda

Good sample preparation is essential for acquiring successful electron backscattered diffraction (EBSD) patterns in the SEM. Mechanical polishing to obtain the required surface quality with minimal sub-surface defects and deformation that does not interfere with the quality of the diffraction data is, more often than not, an art form. Special polishing techniques, such as low force lapping fixtures, electrochemical-mechanical polishing, and vibratory polishing, have been used to minimize the sub-surface damage, but have not eliminated it. Ion polishing has been used to reduce the damage layer further. However, the commercially available ion systems suffer several drawbacks, including: 1) small area treatment (≤ 1 cm) 2) decreasing beam current density with accelerating voltages, and 3) the inability to process non-conducting samples. Barna and Pecz have shown that at 3 keV with an incident angle of 5° relative to the surface, approximately 25 nm of ion damage occurs in Si and GaAs, but at 250 eV, there is less than 1 nm of amorphization of the surface. They also showed that a glancing angle across the surface is essential for removing topographic features. The ion guns that have been available for ion polishing and ion etching of SEM samples typically cannot operate effectively below 3 keV because of the low current density.


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