Aluminum Implantation Research Articles

Competitive Intracellular Hydrogen-Nanocarrier Among Aluminum, Carbon, or Silicon Implantation: a Novel Technology of Eco-Friendly Energy Storage using Research Density Functional Theory

Competitive Intracellular Hydrogen-Nanocarrier Among Aluminum, Carbon, or Silicon Implantation: a Novel Technology of Eco-Friendly Energy Storage using Research Density Functional Theory

Aluminum channeling in 4H-SiC by high-energy implantation above 10 MeV

This study explores high-energy aluminum (Al) implantation above 10MeV as a fabrication process to facilitate the creation of deep doping regions in silicon carbide (SiC). Experimental investigations were conducted to evaluate the technical feasibility of ultra-high energy implantation and high-energy channeling implantation of aluminum into 4H-SiC. Ultra-high-energy Al implantations at 30 and 48MeV were performed, revealing limitations such as increased charge dispersion and decreased current near accelerator technical limits. In contrast, high-energy channeling implantations at 12, 15, and 20MeV demonstrated successful Al channeling implantations into 4H-SiC, emphasizing the importance of precision in crystal orientation and mounting systems. Results indicate that channeling implantations, with precise instrumentation, are a preferred approach over non-channeled ultra-high-energy methods for fabricating deep doping regions in SiC, holding promise for advancing the next generation of high-voltage SiC devices.

Mechanisms of negative bias instability of commercial SiC MOSFETs observed by current transients

This article explains the mechanisms of negative bias instability in commercial n-channel SiC metal–oxide semiconductor field-effect transistors (MOSFETs) by analysis of transient gate currents. The current–voltage measurements were performed at different temperatures along with capacitance–voltage measurements to characterise hole trapping and de-trapping in planar SiC MOSFETs. The experimental results reveal that near-interface traps (NITs) with energy levels aligned to the valence band trap holes from the valence band by tunneling, which is different from published results about NITs with energy levels aligned to the energy gap. The impact of the aluminium implantation process of the p-type region on hole trapping is also demonstrated. The presented analysis also reveals that the hole trapping by NITs is limited to the p-type region, indicating that the aluminium implantation process is responsible for the detected NITs.

Alterations in internal threads of implant analog of different materials after multiple reuse.

The impact of multiple reuse on the alterations in internal threads of four different implant analogous composed of different materials (stainless steel (SS), aluminum (Al), titanium (Ti), and zirconia (Zr) by utilizing two die materials at different time durations is of interest to dentists. The spacing between the threads was measured using the impressions created for the interior threads of implant analogs, or replicas by stereomicroscope set to x50 at 0th, 3rd, 6th, 9th, and 12th interval. It was observed that there was decrease in distance between threads 1-2 as the increasing reuse at increasing time intervals in all implants analogs. However the decrease in distance between threads was low in Titanium implants analogs followed by Zircona implant analogs and the decrease was maximum in aluminum implants analogs followed by SS implant analogs. When there was evaluation of distance between threads 3-4 then it was observed that there was reduced decrease in distance between threads 3-4 as compared to threads 1-2 n all implant analogs. Similarly the reduction in distance between threads 5-6 was lesser as compared to threads 1-2 and threads 3-4. There was decrease in distance between threads 1-2 as the increasing reuse at increasing time intervals in all implants analogs. However, the reduction in distance between threads was lowest in Titanium implants analogs followed by Zircona implant analogs.

Study of the synergy effect of high-intensity aluminum ions implantation into titanium and energy impact on the surface

The work studies the synergy effect of high-intensity implantation of aluminum ions and thesubsequent impact of a powerful pulsed ion beam on the microstructure and properties of titanium.Specimens of titanium were implanted for one hour at a temperature of 1170 K with an ion fluenceof 1021 ions/cm2. Layers with a thickness of about 150 μm were obtained. The energy impact wascarried out by a powerful nanosecond pulsed ion beam with an ion current density on the targetof 100 A/cm2. The paper presents data on changes in the elemental composition, surface morphology,and microstructure of ion-doped and energy-modified layers. It has been established that the additionalenergy impact on the ion-doped layer of a powerful pulsed beam improves microstructure at depthsgreater than 3.4 μm. The synergistic of high-intensity ion implantation of aluminum and the energyimpact of a pulsed ion beam improves the wear resistance of titanium by eighteen folds.

Study of the influence of a powerful pulsed ion beam on titanium deeply-doped with aluminum

The work studies the synergy effect of high-intensity implantation of aluminum ions and the subsequent impact of a powerful pulsed ion beam on the microstructure and properties of titanium. Specimens of titanium were implanted for 1 h at a temperature of 1170 K with an ion fluence of 1021 ions/cm2. Layers with a thickness of about 150 μm were obtained. The energy impact was carried out by a powerful nanosecond pulsed ion beams with an ion current density on the target of 100 A/cm2. The paper presents data on changes in the elemental composition, and microstructure of ion-doped and energy-modified layers. It has been established that the additional energy impact on the ion-doped layer of a powerful pulsed beam improves microstructure at depths of about 4.31 μm. The synergistic of high-intensity ion implantation of aluminum and the energy impact of a pulsed ion beam improves the wear resistance of titanium by eighteen folds.

Al Implantation in Sic; Where Will the Ions Come to Rest?

In all implantations into crystalline targets, quite a few ions find a path along a crystal channel or plane, so called channeling, and these ions travel deep into the crystal. This paper treats aluminum (Al) implantation in 4H-SiC and show how the crystal lattice will guide incoming ions deep into the target and modify the final dopant distribution. 4H-SiC samples have been implanted with 100 keV Al-ions, in a “random” direction using the wafer miscut angle of 4°, as well as with the impact beam aligned anti-parallel to the [0001] direction. Aluminium concentration versus depth profiles has been recorded by secondary ion mass spectrometry (SIMS). To track the most probable ion paths during stopping process, SIIMPL, a Monte Carlo simulation code based on the binary collision approximation (MC-BCA) has been used. In addition, the remaining ion energy has been extracted from SIIMPL at various depth along the ion path. Our results show that, independent of the used impact angle, some ions will be steered by crystal planes predominantly into the direction and also along the six directions. The energy loss is smaller along these low index axes. Therefore, at a depth of 1.2 μm, some Al ions along a path may still have kinetic energy, more than 40% of the original 100 keV, and continues to move deep into the SiC sample. The mean projected range of 100 keV ions in 4H-SiC is about 120 nm.

Cathodoluminescence Characterization of Point Defects Generated through Ion Implantations in 4H-SiC

The high quality of crystal growth and advanced fabrication technology of silicon carbide (SiC) in power electronics enables the control of optically active defects in SiC, such as silicon vacancies (VSi). In this paper, VSi are generated in hexagonal SiC (4H) samples through ion implantation of nitrogen or (and) aluminum, respectively the n- and p-type dopants for SiC. The presence of silicon vacancies within the samples is studied using cathodoluminescence at 80K. For 4H-SiC samples, the ZPL (zero phonon line) of the V1′ center of VSi is more intense than the one for the V1 center before annealing. The opposite is true after 900 °C annealing. ZPLs of the divacancy defect (VCVSi) are also visible after annealing.

Ion implantation and activation of aluminum in bulk 3C-SiC and 3C-SiC on Si

Ion implantation and activation of aluminum in bulk 3C-SiC and 3C-SiC on Si

Compact Trench Floating Field Rings Termination for 10kV+ Rated SiC n-IGBTs

This work presents the design methodology and performance of a compact edge termination structure aiming 10kV+ rated Silicon Carbide (SiC) devices. Standard Floating Field Rings (FFRs) for such high voltage rating SiC devices are not favored because they are inefficient in terms of the achievable breakdown voltage as a percentage of the 1D maximum, consume large chip area, require high implantation energies and small gaps between rings which can violate fabrication limits. We show that the implantation of Aluminium at the bottom of carefully positioned trenches can be analogous to deep Aluminium implantation in terms of performance, thus annulling the need for small gaps between rings and MeV ion implantation. We optimize the distribution of trenches by placing them in multiple zones of different expansion coefficient. The proposed multi expansion ratio Trench FFR termination was utilized to terminate the active area of a 10kV rated Punch Through n-IGBT having 0.8 μm p-body and 100 μm, 3×1014 cm-3 drift region. We found the 0.6–0.8 µm to be the most optimum trench depth, achieving over 10 kV within less than 500 μm of termination length.

Phosphorous and Aluminum Implantation for MOSFET Manufacturing: Revisiting Implantation Dose Rate and Subsequent Surface Morphology

In this work, we study the impact of the dose rate on the electrical properties of aluminum (p-body, p+-body-contact) and phosphorous (n-source/drain) implanted 4H-SiC. We find no significant differences for dose rates ranging from 1×1011 cm-2s-1 to 2−7×1012 cm-2s-1. AFM scans across implanted and non-implanted regions after thermal oxidation and subsequent oxide etching reveal a clear dependence of the oxidation rate on the conduction type and doping concentration. In addition, we observe an increasing (decreasing) oxidation rate for increasing doping concentrations of the n-type (p-type) ion implanted areas.

Aluminum Acceptor Ionization Energies in 4H-SiC for Low Dose, Ultra-High Energy (> 1MeV) Implants

MeV level aluminum implants into 4H-SiC were performed as part of superjunction diode fabrication. Measurement of resistance test structures produced resistivities well above expected values with large decreases at elevated temperatures. Capacitance-voltage measurements indicate a high activation rate of the implanted aluminum. Temperature dependent Hall measurements produce reasonable hole mobilities with acceptor ionization energies of approximately 330meV, well above the 200meV expected for low concentration aluminum doping in 4H-SiC.

Editorial: Choosing the Right Implant

Steven E. Eckert, DDS, MS: Dental implants provide support for dental prostheses. It seems so easy, but we know that there are many pathways toward therapeutic misadventures. By contrast, however, one might suggest that the more complicated the path, the easier it is for a dentist to choose it. To validate this statement, one might only need to visit the trade booths at a dental meeting. The implant companies have the largest floor plan and the most traffic. Once there, you can count the number of manufacturers/distributors representing all these different companies. Beyond the amount of floor space, the numbers of companies, and the busyness at the booths, the scientific programs seem to present more implant discussions than any other form of presentation. It makes you wonder what all the discussion is about. Well, sometimes it’s discussions of the intended use for a specific implant. Some implants have a tapered form that is designed to fully seat in the osteotomy with a minimum number of rotations. Other implants are designed with a narrow coronal aspect to reduce bone loss. Implants are made from different materials: titanium or zirconia, and alloys of titanium, aluminum, vanadium, or titanium and zirconium. There have also been aluminum implants. The coronal aspect of the implants has garnered a great deal of attention. Some flare, some are parallel, and some are tapered, making the coronal aspect of the implant narrower than a point that is more apical. Of course, there are many different brands of bone graft material and many different types of membranes. There are graft materials that are autogenous, homogenous, heterogenous, xenografts, heterografts, homografts, alloplasts, and allografts. You’d be shocked if you heard me say that there are many synonyms that could be included, but this might be confusing. We have different membranes that can be placed over the tooth socket to allow the socket to recontour beneath the membrane, or we could use the membrane over the top of an implant that was placed the same day as the natural tooth was removed. Some of the sales representatives will promote the use of resorbable membrane in areas that are not esthetic, but there are folks who will promote the use of a membrane in an immediate placement after tooth extraction. This is a very noncomprehensive list of implant designs. (Remember that there are well over a thousand different implant designs, and by the time you add in the number of different manufacturers, there are many thousands of implants, implant designs, implant materials, graft materials, membrane materials, etc). You name it, if you can put it in the tooth socket, it may work well or may not, or you might not be able to tell how one works in comparison to another. I sure hope I haven’t lost anybody yet. It is virtually impossible to create a comprehensive list of all these different materials. Of course, then you need someone to help you through the morass of different products that are available in the marketplace. For me, I think it’s valuable to obtain a subscription to one of the dental implant journals. The journals give you something you can hold in your hand and look at again once you realize that the industry has become confusing. This editorial may or may not have been intended to be a little confusing, but confusing it has become. Personally, I like The International Journal of Oral & Maxillofacial Implants . I like that the articles look like they were put together in much the same way, so I know where the materials and methods will be, I know that the conclusion will relate to the introduction, I know how to find results, and I guess I know these things because I edit the journal. Personally, however, I think that other people can figure it out from this journal. There are other journals out there, and these are also good journals. Of course, I’m still partial to JOMI. Steven E. Eckert, DDS, MS Editor-in-Chief

Mechanical and Corrosion Properties of VT6 Titanium Alloy after Irradiation with Helium and Aluminum Lons

The effect of high-dose aluminum implantation on the structural-phase state of the surface layer of titanium alloy VT6 with a fine structure (average grain size 2.3 μm) on the mechanical and corrosion properties has been investigated. It is shown that, as a result of ion irradiation, polyphase implanted layers based on α-titanium grains are formed, containing an intermetallic Ti3Al phase along the grain boundaries of α-titanium. The modified surface layers are characterized by improved mechanical properties and corrosion resistance. The noted effect is enhanced by the use of preliminary helium implantation with a dose of 1.3 × 1017ion / cm2.

Structural-Phase State of UFG-Titanium Implanted with Aluminum Ions

Transmission electron microscopy investigations were carried out to study the structural-phase state of ultra-fine grain (UFG) titanium with the average grain size of ~0.2 μm, implanted with aluminum ions. Implantation was carried out on MEVVA-V.RU ion source at room temperature, exposure time of 5.25 h and ion implantation dosage of 1⋅1018 ion/cm2. UFG-titanium was obtained by a combined multiple uniaxial compaction with rolling in grooved rolls and further annealing at 573 К for 1h. The specimens were investigated before and after implantation at a distance of 70-100 nm from the specimen surface. Concentration profile of aluminum implanted with α-Ti was obtained. It was revealed that the thickness of implanted layer was 200 nm, while maximum aluminum concentration was 70 at.%. Implantation of aluminum into titanium has resulted in formation of the whole number of phases having various crystal lattices, like β-Ti, TiAl3, Ti3Al, TiC and TiO2. The areas of their localization, the sizes, distribution density and volume fractions were determined. Grain distribution functions by their sizes were built, and the average grain size was defined. The paper investigates the influence of implantation on the grain anisotropy factor. It was revealed that implantation leads to the decrease in the average transverse and longitudinal grain size of α-Ti and decrease in the anisotropy factor by three times. The yield stress and contributions of separate strengthening mechanisms before and after implantation were calculated. The implantation has resulted in increase in the yield stress by two times.

Investigation of Al- and N-implanted 4H–SiC applying visible and deep UV Raman scattering spectroscopy

Effects of aluminum (Al) and nitrogen (N) implantation performed at room and at elevated (500 °C) temperatures on epitaxial n-type 4H polytype silicon carbide as well as post-implantation annealing have been studied by Raman scattering spectroscopy. The amorphization of 4H–SiC is observed because of ion implantation effects. The Raman analysis showed that the recovery of the crystallinity increased with an increase in the annealing temperature. However, for samples implanted with high doses, the full crystal recovery was not complete even with annealing temperatures up to 1800 °C, and crystal defects were still present in the recrystallized layer, which was confirmed by transmission electron microscopy. Raman scattering spectra were collected at room temperature using a micro-Raman spectrometer. The visible (488 nm) and deep ultraviolet (266 nm) lasers were used as excitation sources. For the DUV laser, the optical penetration depth is less than the implanted layer thickness, and the area near the surface layer can be exactly probed. In contrast, the visible Raman spectrum shows bands characteristic of bulk 4H–SiC, which arise from the underlying non-implanted region. Based on the analysis of the longitudinal optical phonon–plasmon coupled mode, the electrical parameters for N2+ implanted samples were evaluated, where electron concentration n = 3.05 × 1018 cm−3 and mobility μ = 50 cm2/V s, respectively. The results are consistent with the parameters measured by the Hall method.

The effect of aluminum ion implantation on the grain size and structure of UFG titanium

Using the transmission electron microscopy technique, we have studied the structural-phase state of UFG titanium with an average grain size ~0.2 μm implanted with aluminum ions. An MEVVA-V.RU source has been used to implant the specimen at room temperature, implantation time 5.25 h, and irradiation dose 1 · 1018 ion/cm2. To produce the UFG titanium samples, we have employed the combined multiple uniaxial pressing technique (abc-pressing) followed by grooved rolling and subsequent annealing at 573 K for 1 h. The samples have been studied in two states: 1) before implantation (initial state) and 2) after implantation at a distance 70–100 nm from the sample surface. We have obtained the aluminum concentration profile of implanted α-Ti. It has been established that the maximum concentration of aluminum is 70 at.% and the thickness of the implanted layer is 200 nm. We have determined the grain distribution functions over the grain size, calculated the grain anisotropy coefficient before and after implantation. It has been established that implantation decreases the average longitudinal and transversal sizes of α-Ti grains, and reduces the anisotropy coefficient by three times. It has been established that aluminum implantation into titanium brings about formation of a whole set of phases with different crystal lattices, namely, β-Ti, TiAl3, Ti3Al, TiC, and TiO2.

Microstructure of titanium alloy modified by high-intensity implantation of low- and high-energy aluminium ions

This study focuses on the analysis of microstructural, elemental and phase compositions of surface and near-surface layers of titanium after the implantation of aluminium. A titanium alloy with a chemical composition close to commercially pure titanium (grade 2) was used as the target material. Ion implantation was performed using two modes of irradiation: 1. repetitively pulsed ion beams with a mean ion energy of 35 keV; 2. low-energy-focused ion beams of high intensity with a mean ion energy of 2.6 keV. The irradiation fluence reached 1.1 × 1018 ion/cm2 using the first mode and 1.6 × 1021 ion/cm2 using the second mode. In both cases, the beam itself heated the targets. The peak concentration of aluminium after the implantation of medium-energy ions was ~65 at.%, and the maximum depth of dopant penetration was 2.6 μm. On the contrary, in the case of high-intensity low-energy ion implantation, the surface concentration of dopant reached a maximum of 25 at.%, but the depth of penetration increased significantly and achieved 50 μm. The results of X-ray diffraction (XRD) and transmission electron microscopy (TEM) showed that fine-grained intermetallic phases, Ti3Al and TiAl, and solid solutions of various compositions were possibly formed after the medium-energy ion implantation. The mean grain size of the intermetallic phases was ~50 nm. XRD and TEM analyses in the case of low-energy high-intensity ion implantation demonstrated the formation of the ion-alloyed layer, which comprised intermetallic phase Ti3Al and solid solutions of aluminium in titanium. The grain size of Ti3Al phase can be 5 μm and more.

Lateral straggling of implanted aluminum in 4H-SiC

The implantation of aluminum into 4H-SiC is studied using secondary ion mass spectrometry. In particular, two-dimensional concentration profiles are obtained, which allow the investigation of lateral straggling and its dependence on the crystallographic orientation. A high dose, medium energy aluminum implantation is studied in great detail. It shows an asymmetric distribution due to the 4°-off axis growth of the epitaxial layer. The lateral straggling is found to be in the range of several micrometers for a concentration of 1×1015 cm−3, which is contrary to the expectation given by most simulation studies. Implantations performed at different orientations support the idea that lateral straggling highly depends on the particular channeling opening.

Improving the performance properties of titanium alloy VT6 after ion implantation with copper and aluminum ions

The objective of this work was to study the processes occurring on the surface of VT6 titanium alloy samples when implanting with copper and aluminum ions. Elemental composition, structural-phase state, mechanical and tribological properties of VT6 titanium alloy surface layers modified by aluminum and copper ions was being researched. As can be seen from the undertaken studies, the mode of high-intensity ion-implantation process makes it possible to obtain ion doped surface layers of VT6 alloy containing finely dispersed intermetallic phases and a solid solution of aluminum and copper in titanium of a composition varying in depth. The thickness of the ion-doped layer, the average grain size of the intermetallic phases and their conglomerates increases with the increase in implantation dose while aluminum implantation is in progress. It has been shown that the implantation of aluminum and copper ions into VT6 alloy leads to a considerable increase in its microhardness and wearability. Based on the research results, a conclusion on the positive effect of a structural-phase state of ion-doped titanium layers on their mechanical and tribological properties of VT6 titanium alloy has been drawn.