Application Of Ion Implantation Research Articles

Advancements and challenges in strained group-IV-based optoelectronic materials stressed by ion beam treatment

In this perspective article, we discuss the application of ion implantation to manipulate strain (by either neutralizing or inducing compressive or tensile states) in suspended thin films. Emphasizing the pressing need for a high-mobility silicon-compatible transistor or a direct bandgap group-IV semiconductor that is compatible with complementary metal–oxide–semiconductor technology, we underscore the distinctive features of different methods of ion beam-induced alteration of material morphology. The article examines the precautions needed during experimental procedures and data analysis and explores routes for potential scalable adoption by the semiconductor industry. Finally, we briefly discuss how this highly controllable strain-inducing technique can facilitate enhanced manipulation of impurity-based spin quantum bits (qubits).

Fabrication and electrical characterization of carbon coating on a quartz wafer treated with nitrogen ion implantation

This article details the research within the I4Bags project, demonstrating the versatility of low-energy ion implantation protocols as a means to selectively alter the electronic, electrochemical, and electrical properties of thin-film semiconductor batteries. Major goals include increasing gravimetric capacity and improving stability. The current research focuses on the quantitative and qualitative analysis of graphite cathodes, which are then subjected to low-energy ion implantation to transform the solid electrolyte interfacial boundary. The process begins with the formation of carbon coatings by magnetron sputtering on quartz plates, followed by the implantation of nitrogen ions. In this paper, the procedure for obtaining carbon coatings and the application of low energy ion implantation will be presented. These will be verified based on two-dimensional surface resistance maps, which are analyzed in terms of the thickness of the deposited carbon and the changes in electrical structure caused by nitrogen ion implantation.

Resistance switching stability of STO memristor under Au ion implantation

The alteration in microstructure, induced by ion migration due to applied voltage, constitutes a pivotal factor influencing the performance of the memristor. This phenomenon adversely impacts the stability of the memristor, posing challenges for its practical applications. Notably, the defects present in oxide films, serving as the functional layer in the memristor, assume a crucial role in determining the stability of the artificial synapse—a fundamental component of neuromorphic computing. The precise regulation of defect distribution and density at the nanoscale by growing films directly poses a formidable challenge. In this investigation, a memristor composed of strontium titanate (SrTiO3) was fabricated, exhibiting improved stability in resistive switching during I–V cycles and enhanced multilevel storage performance through the implementation of Au ions implantation. Furthermore, these devices were simulated as neural synapses and integrated into artificial neural networks. A comprehensive array of characterizations was executed to scrutinize the microscopic effects of ion implantation. This involved analyzing changes in elemental composition, structural damage, and spectral characteristics of the films. These findings offer a viable strategy for enhancing the resistive switching performance of oxide thin film devices through the judicious application of ion implantation.

Antioxidation effect of coatings prepared by helium-ion implantation of copper surfaces

The antioxidation effect of a shallow alloying layer introduced by ion implantation is inadequate for many oxidizable metals, limiting its application in antioxidation technology. In this work, the feasibility of preparing an antioxidation coating using ion implantation is explored with the aim of producing copper (Cu) surfaces with strong antioxidation properties. A coating consisted of amorphous carbon and silica is prepared on a Cu surface by helium-ion implantation with pump oil. The formation of the coating is attributed to the bombardment effect of ion implantation and ion beam scanning, which dissociates the bonds of the precursor coating material and drives the redistribution of dissociated species on the Cu surface. During He+ implantation, the C–C and C–O bonds are more likely to break down, resulting in the formation of amorphous carbon. The Si and O combine to form silica because of the high bonding energy of Si–O. The prepared coating exhibits a strong antioxidation effect by blocking the diffusion of Cu cations and enhancing the adhesion of the overlying oxidized film to the substrate. This study demonstrates the feasibility of preparing antioxidation coatings using ion implantation, which could advance the application of ion implantation in antioxidation technology and Cu in microelectronics.

Application of ion implantation as a tool to study neutron induced morphological changes in HOPG and RBMK-1500 reactor graphite

Based on the RBMK-1500 (rus.: peaктop бoльшoй мoщнocти кaнaльный, PБMК; reaktor bolshoy moshchnosti kanalnyy, “high-power channel-type reactor”) reactor irradiation conditions, ion implantation was used as a tool to study neutron induced morphological changes in both highly oriented pyrolytic graphite (HOPG) and nuclear grade RBMK graphite. Graphite samples were implanted with 180 keV 14N+ ions at the fluences of 1.0 × 1016 ions/cm−2 and 2.5 × 1016 ions/cm−2. To study temperature effects on both ion migration and structural disorder level in the graphite matrix, the implantation procedures were carried out under different temperature conditions – room temperature (RT) and 500 °C. Subsequently, the distribution profiles of the implanted 14N+ ions were obtained by using secondary ion mass spectroscopy (SIMS) technique, while the microstructural properties of the graphite were evaluated by Raman spectroscopy. Implantation induced primary displacement damage profiles and implanted ion profiles were evaluated theoretically by using GEANT4 10.6 and SRIM-2013 codes. The profiles of implanted nitrogen obtained by SIMS technique were found to be in good agreement with theoretical ones. The surfaces of HOPG samples displayed macroscopic damage in form of fractures after 14N+ ion implantation at 500 °C; however, in case of RBMK graphite, the sample surfaces remained without visually observable changes. The Raman spectra showed an increase of sp3-related content and formation of amorphous carbon in both HOPG and RBMK graphite samples; the latter exhibits higher structural disorder at microscopic level and stronger amorphization than HOPG.

Performance and reliability of the fourth generation of Safe Delivery Source® (SDS®4) in the ion implantation application

Performance and reliability of the fourth generation of Safe Delivery Source® (SDS®4) in the ion implantation application

Application of Neon Ion Implantation to Generate Intermediate Energy Levels in the Band Gap of Boron-Doped Silicon as a Material for Photovoltaic Cells.

The aim of the work is to present the possibility of generating intermediate levels in the band gap of p-type silicon doped with boron by using neon ion implantation in the aspect of improving the efficiency of photovoltaic cells made on its basis. The work contains an analysis of the influence of the dose of neon ions on the activation energy value of additional energy levels. The article presents the results of measurements of the capacitance and conductance of silicon samples with a resistivity of ρ = 0.4 Ω cm doped with boron, the structure of which was modified in the implantation process with Ne+ ions with the energy E = 100 keV and three different doses of D = 4.0 × 1013 cm−2, 2.2 × 1014 cm−2 and 4.0 × 1014 cm−2, respectively. Activation energies were determined on the basis of Arrhenius curves ln(et(Tp)/Tp2) = f(1/kTp), where Tp is in the range from 200 K to 373 K and represents the sample temperature during the measurements, which were carried out for the frequencies fp in the range from 1 kHz to 10 MHz. In the tested samples, additional energy levels were identified and their position in the semiconductor band gap was determined by estimating the activation energy value. The conducted analysis showed that by introducing appropriate defects in the silicon crystal lattice as a result of neon ion implantation with a specific dose and energy, it is possible to generate additional energy levels ∆E = 0.46 eV in the semiconductor band gap, the presence of which directly affects the efficiency of photovoltaic cells made on the basis of such a modified material.

Implantation of low-energy Ni12+ ions to change structural and strength characteristics of ceramics based on SiC

The paper presents results of studying the applicability of ion implantation to increase the strength characteristics and corrosion resistance of carbide ceramics. According to the X-ray phase analysis, it was found that an increase in the irradiation fluence leads to a slight change in the magnitudes of displacements and defect concentration, which indicates the absence of amorphization processes of the crystal structure. It is established that a decrease in the lattice volume leads to an increase in ceramics density and a decrease in porosity. In this case, a change in the average crystallite size leads to a change in the concentration of dislocation defects near the grain boundaries, which also indicates a change in the defect structure as a result of irradiation. A decrease in the integral porosity of the surface layer, as well as changes in the dislocation and vacancy densities in the surface layer of ceramics, leads to an increase in the strength and crack resistance of the surface layer. That has a significant effect on reducing the rate of degradation of ceramics in aggressive media.

Pulsed Power Modulator With Active Pull-Down Using Diode Reverse Recovery Time

This paper presents a pulsed power modulator with a new structure that utilizes the reverse recovery characteristics of diodes to achieve an effective pull-down circuit configuration. The proposed configuration for active pull-down applicable to negative pulsed power applications with a high-voltage direct switching method is implemented by adding a diode to the pulse discharging path of the modulator, instead of using a pull-down resistor. The diode is forward-biased while an output pulse voltage is applied to the load. When the pulse voltage applied to the load is removed, the residual energy in the load is quickly discharged through the reverse recovery path of the diode so that the pull-down function of the pulsed power supply system is efficiently performed. The operating principle of the proposed system is described, and each operating mode is analyzed in detail. In addition, the feasibility of the proposed system configuration is examined through various simulation results. Finally, it is proven that the proposed system can be used effectively in pulsed power application fields through a practical experiment in plasma source ion implantation applications.

Selective area isolation of β-Ga2O3 using multiple energy nitrogen ion implantation

In this study, we report on the application of multiple energy nitrogen ion implantation for the electrical isolation of electronic devices on monoclinic β-Ga2O3. By the introduction of uniformly distributed midgap damage-related levels in the Ga2O3 crystal lattice, we are able to increase the sheet resistances by more than 9 orders of magnitude to ≥1013 Ω/sq which remains stable up to annealing temperatures of 600 °C carried out for 60 s under a nitrogen atmosphere. At higher annealing temperatures, the damage-related trap levels are being removed causing a significant drop of the sheet resistance down to 4 × 105 Ω/sq for annealing temperatures of 800 °C. This effect is preceded by a structural recovery of the implantation damages via the recrystallization of the crystal lattice at already 400 °C as verified by x-ray diffraction measurements. The extracted activation energies of the deep states controlling the high resistivity of Ga2O3 after implantation are in the range of 0.7 eV, showing a strong correlation with the annealing temperature dependence of the sheet resistance and thus supporting the theory of a damage-induced isolation mechanism.

Analysis of grid electrode assisted plasma based ion implantation system and application to ion beam assisted deposition for insulator substrates

A grid electrode assisted plasma based ion implantation system, which was originally designed only for ion implantation on insulator substrates, was investigated as a system of sputter deposition with high energy ion beam irradiation. When pulses of negative high voltage were applied to grid electrodes immersed in argon plasmas, high energy ions were observed to bombard the surface of the grid electrodes during the rise and plateau times of the pulses, using particle-in-cell (PIC) simulations. The resulting sputter deposition of atoms on the substrate from the stainless steel grid electrodes was confirmed by X-ray photoelectron spectroscopy. During the fall time of the pulses, PIC simulations indicated high energy ion beams of pseudowaves bombarded the surface of the substrate. Thus we verified that by using grid electrodes, ion beams can irradiate the insulator substrate after the sputter deposition within the time scale of a single pulse. In the proposed configuration, problems due to high voltage on insulator can be avoided because the insulator substrates float in plasmas for the entire process. Finally, we discuss potential application of the system for ion beam assisted deposition as a compact plasma based ion implantation and deposition system, which does not require a separate sputtering system.

Application of Ion Implantation for Intermediate Energy Levels Formation in the Silicon-Based Structures Dedicated for Photovoltaic Purposes

Application of Ion Implantation for Intermediate Energy Levels Formation in the Silicon-Based Structures Dedicated for Photovoltaic Purposes

Application of ion implantation for the modification of silicon-on-sapphire epitaxial systems, their structure, and properties

Articles devoted to methods for improving the structural quality of epitaxial films, which utilize the high-temperature interaction between hydrogen and silicon as well as solid-phase recrystallization process, are reviewed. A correlation between the quality of the epitaxial layer and the radiation resistance of the microcircuits obtained thereon is also considered. A method for creating capture/recombination centers in sapphire during the implantation of helium ions is proposed, yielding high-quality radiation-resistant silicon-on-sapphire films.

The influence of repetitively pulsed plasma immersion low energy ion implantation on TiN coating formation and properties

Application of high frequency short pulse plasma immersion low energy ion implantation for titanium nitride coating deposition using vacuum arc metal plasma and hot-cathode gas-discharge plasma on R6M5 alloy was investigated. Implementation of negative repetitively pulsed bias with bias amplitude 2 kV, pulse duration 5 μs and pulse frequency 105 Hz leads to 6.2-fold decrease of vacuum arc macroparticle surface density for macroparticles with diameter less than 0.5 μm. Ion sputtering due coating deposition reduces the production rate approximately by 30%. It was found that with bias amplitude range from 1.1 to 1.4 kV and pulse duration 5 μs yields to formation of coatings with local hardness up to 40 GPa. This paper presents the results of experimental studies of adhesion strength, tribological properties and surface morphology of deposited TiN coatings.

Design and implementation of a web application to estimate the surface density of implanted ions in solid substrates

In the present research a web application is designed and implemented allowing us to calculate the dose of implanted ions on solid substrates from experimental parameters (repetition rate and pulse duration of current, potential difference, work pressure and treatment time) and current pulses acquired during start-up and shutdown of high voltage electrical discharges at low pressures. By physical and mathematical processing, it is achieved at first estimate the value of the ionic charge, and then the areal density. This study will provide more accurate and suitable developments in relation to applications of ion implantation as an alternative technique to increase the service life of the surfaces of the materials used in various industrial sectors developments.

Estimation of the ionic charge of non-metallic species into an electrical discharge through a web application

Estimate the ionic charge generated in electrical discharges will allow us to know more accurately the concentration of ions implanted on the surfaces of nonmetallic solids. For this reason, in this research a web application was developed to allow us to calculate the ionic charge generated in an electrical discharge from the experimental parameters established in an ion implantation process performed in the JUPITER (Joint Universal Plasma and Ion Technologies Experimental Reactor) reactor. The estimated value of the ionic charge will be determined from data acquired on an oscilloscope, during startup and shutdown of electrical discharge, which will then be analyzed and processed. The study will provide best developments with regard to the application of ion implantation in various industrial sectors.

Ion‐beam induced effects in multi‐layered semiconductor systems

In this article, ion‐beam induced effects in multi‐layered III–V semiconductor structures are reviewed. Besides doping, important effects occurring during ion irradiation are defect formation and diffusion, amorphisation and intermixing. It is shown that these processes are closely related to each other. In layered systems consisting of group III‐phosphides and ‐arsenides, which can be amorphised by ion implantation, cascade mixing is the dominant mixing mechanism at low temperatures. At a critical temperature, the crystalline structure is retained after implantation and the mixing efficiency may drop down because cascade mixing is more efficient in amorphous semiconductors than in their crystalline counterparts. A further increase of temperature results in an increase of the mixing efficiency due to thermally enhanced processes. Although much less experimental data exist on ion‐beam induced effects in layered group III‐nitride systems, the results suggest that these systems are not amorphised during ion implantation. In this case, the experimental results can be explained assuming recoil rather than cascade mixing to occur with the former being much weaker than the latter. A few applications of ion implantation of multi‐layered semiconductor systems are addressed.

Tunnel oxide passivated contacts formed by ion implantation for applications in silicon solar cells

Passivated contacts (poly-Si/SiOx/c-Si) doped by shallow ion implantation are an appealing technology for high efficiency silicon solar cells, especially for interdigitated back contact (IBC) solar cells where a masked ion implantation facilitates their fabrication. This paper presents a study on tunnel oxide passivated contacts formed by low-energy ion implantation into amorphous silicon (a-Si) layers and examines the influence of the ion species (P, B, or BF2), the ion implantation dose (5 × 1014 cm−2 to 1 × 1016 cm−2), and the subsequent high-temperature anneal (800 °C or 900 °C) on the passivation quality and junction characteristics using double-sided contacted silicon solar cells. Excellent passivation quality is achieved for n-type passivated contacts by P implantations into either intrinsic (undoped) or in-situ B-doped a-Si layers with implied open-circuit voltages (iVoc) of 725 and 720 mV, respectively. For p-type passivated contacts, BF2 implantations into intrinsic a-Si yield well passivated contacts and allow for iVoc of 690 mV, whereas implanted B gives poor passivation with iVoc of only 640 mV. While solar cells featuring in-situ B-doped selective hole contacts and selective electron contacts with P implanted into intrinsic a-Si layers achieved Voc of 690 mV and fill factor (FF) of 79.1%, selective hole contacts realized by BF2 implantation into intrinsic a-Si suffer from drastically reduced FF which is caused by a non-Ohmic Schottky contact. Finally, implanting P into in-situ B-doped a-Si layers for the purpose of overcompensation (counterdoping) allowed for solar cells with Voc of 680 mV and FF of 80.4%, providing a simplified and promising fabrication process for IBC solar cells featuring passivated contacts.

Development of a microwave ion source for ion implantations.

A microwave ion source is expected to have a long lifetime, as it has fewer consumables. Thus, we are in the process of developing a microwave ion source for ion implantation applications. In this paper, we report on a newly developed plasma chamber and the extracted P(+) beam currents. The volume of the plasma chamber is optimized by varying the length of a boron nitride block installed within the chamber. The extracted P(+) beam current is more than 30 mA, at a 25 kV acceleration voltage, using PH3 gas.

Influence of biocompatible metal ions (Ag, Fe, Y) on the surface chemistry, corrosion behavior and cytocompatibility of Mg–1Ca alloy treated with MEVVA

Mg–1Ca samples were implanted with biocompatible alloy ions Ag, Fe and Y respectively with a dose of 2×1017ionscm−2 by metal vapor vacuum arc technique (MEVVA). The surface morphologies and surface chemistry were investigated by SEM, AES and XPS. Surface changes were observed after all three kinds of elemental ion implantation. The results revealed that the modified layer was composed of two sublayers, including an outer oxidized layer with mixture of oxides and an inner implanted layer, after Ag and Fe ion implantation. Y ion implantation induced an Mg/Ca-deficient outer oxidized layer and the distribution of Y along with depth was more homogeneous. Both electrochemical test and immersion test revealed accelerated corrosion rate of Ag-implanted Mg–1Ca and Fe-implanted Mg–1Ca, whereas Y ion implantation showed a short period of protection since enhanced corrosion resistance was obtained by electrochemical test, but accelerated corrosion rate was found by long period immersion test. Indirect cytotoxicity assay indicated good cytocompatibility of Y-implanted Mg–1Ca. Moreover, the corresponding corrosion mechanisms involving implanting ions into magnesium alloys were proposed, which might provide guidance for further application of plasma ion implantation to biodegradable Mg alloys.