Search results for "ion implantation"
showing 10 items of 34 documents
Surface passivation of gallium selenide by nitrogen implantation
2002
In this paper we report on the characterization of nitrogen-implanted single-crystal GaSe samples. Nitrogen atoms were implanted at 80 keV, with doses ranging from 4 × 10 13 to 10 15 N + ions cm -2 . Next, samples were aged in open air and characterized by small-area XPS, together with an unimplanted clean surface, in order to quantify the effects of the nitrogen implantation. In general, we found that the oxidation was fully prevented in N + -implanted samples.
Ion implantation effects in BaTiO3 single crystals
1991
Abstract Thermally controlled helium implantation has been used to produce planar waveguides in BaTiO3 without noticeable depoling effects in the samples. Profiles for the ordinary and extraordinary refractive index are deduced from optical mode measurements. No annealing procedure is required. We report the effects of different ion fluences and energies in the MeV range on the waveguide properties.
Double implantation in silica glass for metal cluster composite formation: a study by synchrotron radiation techniques
2001
Silica glass containing metal clusters is studied for both basic and applied aspects, related to the physics of cluster formation and to the optical properties of these materials. To obtain such composite structure, Cu+ Ni, Au+ Cu, Au+ Ag, Cu+ Co, and Cu+ Ag sequential implantations in fused silica were realized. The resulting systems, after possible annealing in various atmospheres, were studied by synchrotron radiation-based techniques, namely, extended X-ray absorption fine structure (EXAFS) spectroscopy, grazing incidence X-ray diffraction (GIXRD), and grazing incidence small angle X-ray scattering (GISAXS). The unique potential of these techniques is the capability to investigate dilut…
Hydrogen- and helium-implanted silicon: Low-temperature positron-lifetime studies
1991
High-purity single-crystal samples of float-zoned Si have been implanted with 6.95-MeV protons and with 25-MeV {sup 3}He{sup 2} ions at 15 K, and the positron-lifetime technique has been used to identify the defects created in the samples, and to study the effects of H and He on the annealing of point defects in Si. The results have been compared with those of proton-irradiated Si. A 100--300-K annealing stage was clearly observed in hydrogen (H{sup +}) -implanted Si, and this stage was almost identical to that in the {ital p}-irradiated Si. The final annealing state of the H{sup +}-implanted Si started at about 400 K, and it is connected to annealing out of negatively charged divacancy-oxy…
The surface modification of polymers to modulate endothelial cell growth
1996
The effect of nitrogen ion implantation or ion-assisted film deposition on the growth of human endothelial cells in vitro on a substrate has been studied. It was shown that the largest change occurs when TiO2 films were reactively sputtered onto the substrates, while the most passive surface was reactively sputtered SiO2. SEM pictures of the cells adhering to the various treated surfaces show that the cells were healthy. Future studies on the effect of alloy films and their oxides and nitrides are proposed.
Critical temperature modification of low dimensional superconductors by spin doping
2007
Ion implantation of Fe and Mn into Al thin films was used for effective modification of Al superconductive properties. Critical temperature of the transition to superconducting state was found to decrease gradually with implanted Fe concentration. it was found that suppression by Mn implantation much stronger compared to Fe. At low concentrations of implanted ions, suppression of the critical temperature can be described with reasonable accuracy by existing models, while at concentrations above 0.1 at.% a pronounced discrepancy between the models and experiments is observed.
Radiation induced defects in SiO 2
2002
The main luminescent centers in SiO 2 films are the red luminescence R (650 v nm; 1.85 v eV) of the non-bridging oxygen hole center (NBOHC) and the twofold-coordinated (divalent) silicon with a blue B (460 v nm; 2.7 v eV) and a UV band (285 v nm; 4.4 v eV). Especially the latter ones are produced under irradiation, but from existing precursors assumed as silicon related oxygen deficient centers (SiODC). Therefore, in order to prove these models we compare a direct oxygen implantation with a direct silicon implantation into SiO 2 layers. The main result is: implanting oxygen increases the red band R but does not affect the blue band B. Silicon surplus increases the amplitude of the blue (B) …
Impact of Helium Ion Implantation Dose and Annealing on Dense Near-Surface Layers of NV Centers
2022
A. Berzins acknowledges support from Latvian Council of Science project lzp-2021/1-0379, “A novel solution for high magnetic field and high electric current stabilization using color centers in diamond,” and LLC “MikroTik” donation project, administered by the UoL foundation, “Improvement of Magnetic field imaging system” for the opportunity to significantly improve experimental setup as well as “Simulations for stimulation of science” for the opportunity to acquire COMSOL license. I. Fescenko acknowledges support from ERAF project 1.1.1.5/20/A/001, and I.F. and A.B. acknowledge support from LLC “MikroTik” donation project “Annealing furnace for the development of new nanometer-sized sensor…
Annealing reactions in lead implanted copper
2002
Abstract The terminal solubility of Pb in Cu is extremely low and does not exceed 0.09 at.% at 875 K. Ion implantation of lead ions at 100 keV into Cu single crystals produces metastable solutions. Annealing of the samples causes redistribution of the implanted atoms to equilibrium or near-equilibrium aggregate states which may be reflected in a change in the type of impurity lattice location in the host matrix. We have studied the effect of annealing on single crystalline Cu implanted at temperatures around 375 K with Pb to a concentration of a 1–2 at.%. Rutherford backscattering/channeling analysis and transmission electron microscopy of the as-implanted samples have shown that the implan…
P-Type Doping of 4H-SiC for Integrated Bipolar and Unipolar Devices
2015
International audience; P-type 4H-SiC layers formed by ion implantation need high temperature processes, which generate surface roughness, losing and incomplete activation of dopants. Due to dopant redistribution and channeling effect, it is difficult to predict the depth of the formed junctions. Vapor-Liquid-Solid (VLS) selective epitaxy is an alternative method to obtain locally highly doped p-type layers in the 1020 cm-3 range or more. The depth of this p-type layers or regions is accurately controlled by the initial Reactive-Ion-Etching (RIE) of the SiC. Lateral Junction Field Effect Transistor (JFET) devices are fabricated by integrating p-type layers created by Al ion implantation or …