Effects Of Hydrogen Implantation Research Articles

Effect of hydrogen implantation on low-temperature activation of boron in silicon

Understanding the behavior of dopant activation at low temperatures is necessary for three-dimensional integration of transistors. In this work, the impact of hydrogen coimplantation on boron activation was investigated at implantation doses below the amorphization threshold. The carrier depletion effect due to substrate doping was simulated to accurately characterize the initial activation behavior of boron. At temperatures higher than 400 °C, the boron activation level decreased as the hydrogen dose increased. The deactivation caused by hydrogen diminished after extended annealing at 500 °C. This indicated the passivation of boron by hydrogen. However, the boron activation in the sample implanted with hydrogen at a dose of 1 × 1015 cm−2 was first degraded and then enhanced during annealing at 300 °C. The time-dependent activation behavior suggested the elimination of isolated defects via reactions associated with hydrogen migration.

Random magnetic anisotropy approach in amorphous Fe88.4Zr11.6 films: Effects of hydrogen implantation

The effects of hydrogen implantation on the magnetic properties in amorphous Fe88.4Zr11.6Hx films with different hydrogen contents (0≤ x≤16) were investigated. The Curie temperature increases with increasing hydrogen content while the coercivity presents an important decrease upon H implantation. Based on the analysis of the approach to saturation in magnetization, the local random anisotropy constant KL was extracted. The local random anisotropy constant decreases from 1.468 MJ/m3 to 0.667 MJ/m3 when the concentration of H increases from 0 to 16%. The ferromagnetic correlation length was found to significantly increase with increasing hydrogen content. The local anisotropy was also extracted from the coercivity based on the Alben and Becker theory, which fits reasonably with that obtained using random magnetic anisotropy approach.

Effects of hydrogen implantation on the magnetocaloric properties of amorphous FeZr films

We report on the effects of H-implantation on the magnetic and magnetocaloric properties of amorphous FeZr films. Arrott plots reveal a second order ferromagnetic to paramagnetic phase transition for the as-grown and H-implanted films, with an increase in TC from 160 to 200 K upon implantation. The maximum change in magnetic entropy (-ΔSM) increases from 0.66 to 0.77J/kgK for a field change μ0ΔH = 1.5T, as well as the relative cooling power (RCP) values were improved from 84.5 to 108.6J/kg. This improvement was attributed to the increase in magnetization and chemical inhomogeneity induced by the implantation process. The increase in the chemical inhomogeneity was supported by the determination of the local exponent n extracted from the slope of Ln(−ΔSM) as a function of Ln(μ0H), which is line with the simulated depth profile of hydrogen atoms through the FeZr film.

Nano-Oxide-Dispersed Ferritic Steel for Fusion Energy Systems

ABSTRACTThe role of oxide nanoparticles in cavity formation of a nano-oxide-dispersed ferritic steel subjected to (Fe + He) dual-ion and (Fe + He + H) triple-ion irradiations has been studied using transmission electron microscopy to elucidate the synergistic effects of helium and hydrogen on radiation tolerance of nano-oxide-dispersed ferritic steel for fusion energy systems. The effect of oxide nanoparticles on suppressing radiation-induced void swelling is clearly revealed from the observation of preferred trapping of helium bubbles at oxide nanoparticles, which results in a unimodal distribution of cavities in the (Fe + He) dual-ion irradiated specimen. An adverse effect of hydrogen implantation, however, is revealed from the observation of a bimodal distribution of cavities with large and facetted voids in association with the formation of HFe5O8-based hydroxide in local regions of the (Fe + He + H) triple-ion irradiated specimen.

Effect of Hydrogen Implantation on the Mechanical Properties of AlN throughout Ion-Induced Splitting

The ability to transfer bulk quality III-N thin layers onto foreign platforms is a powerful strategy to enable high-efficiency and low-cost optoelectronic devices. Ion-cut using sub-surface defect engineering has been an effective process to split and transfer a variety of semiconductors. With this perspective, hydrogen-implanted AlN samples were annealed in air at temperatures ranging from 300°C to 600°C for 5 min to study the influence of pre-layer splitting treatments on the nanomechanical properties. There is a clear dependence of the hardness on implanted hydrogen implantation fluence. We observe that the as-implanted hardness increased from 18 GPa for the virgin reference sample to ∼25 GPa for the highest fluence of 3 × 1017 H cm−2 prior to annealing. In the case of reference single crystalline Si samples, a significant drop in the hardness and elastic modulus is observed in the H implantation-induced damage zone subsequent to thermal annealing , while for crystalline epitaxial AlN samples with 0.5 × 1017 and 2.0 × 1017 H implant fluences, the hardness increases and peaks until the thermal annealing temperature reaches 350°C and subsequently begins to drop thereafter for higher annealing temperatures. However, for the 1.0 × 1017 H implantation fluence the hardness continues to increase with increasing thermal annealing temperature.

Suppression of nanoindentation-induced phase transformation in crystalline silicon implanted with hydrogen

In this paper the effect of hydrogen implantation in silicon on nanoindentation-induced phase transformation is investigated. Hydrogen ions were implanted in silicon through 300 nm thick oxide with double energy implantation (75 and 40 keV). For both energies implantation dose was 4 × 1016 cm−2. Some samples were thermally annealed at 400 °C. The micro-Raman spectroscopy was applied on nanoindentation imprints and the obtained results were related to the pop out/elbow appearances in nanoindentatioin unloading-displacement curves. The Raman spectroscopy revealed a suppression of Si-XII and Si-III phases and formation of a-Si in the indents of hydrogen implanted Si. The high-resolution x-ray diffraction measurements were taken to support the analysis of silicon phase formation during nanoindentation. Implantation induced strain, high hydrogen concentration, and platelets generation were found to be the factors that control suppression of c-Si phases Si-XII and Si-III, as well as a-Si phase enhancement during nanoindentation. Open image in new window

Effect of hydrogen implantation in 6H-SiC before and after thermal oxidation

In this study, we propose new approach to study on hydrogen implantation into SiC crystalline structure and its effect on thermal oxidation. This paper has investigated on effects of hydrogen implantation into the surface structure of 6H-SiC crystal before and after thermal oxidation in oxygen ambient. H ions were implanted in SiC with dose of 1×10 16 atoms/cm 2 and energy of 15 keV. AFM results of implanted and non-implanted areas show that roughness in the implanted area is more than the non-implanted but, we could not observe any evidence of implanting effect in the nano scrapes which were created during polish process. Also, crystal quality, effect of H implantation and depth of maximum concentration were determined by RBS- Channeling. Moreover, it shows that the collision of H ions has affected on the SiC atoms. Distribution and dose of H ions were estimated by ERD technique. Furthermore, bonding between SiC atoms was investigated in implanted and non-implanted areas by FTIR technique. In addition, FTIR results in two areas show a significant difference between both areas before and after oxidation in oxygen ambient.

Nanomechanical Response of the Si Lattice to Hydrogen Implantation and Annealing for Layer Splitting

We studied the effect of hydrogen implantation into Si and the nanomechanical response to defect interaction, which is responsible for wafer splitting during the Smart CutTM layer transfer of (001) oriented Si wafers. Hardness and modulus of H implanted Si samples were measured by nanoindentation technique before and after thermal annealing. A significant weakening of the hardness and elastic modulus of the single crystalline Si lattice in the H implantation-induced damage zone following annealing was observed. Cross-sectional transmission electron microscopy revealed that the majority of extended defects consist of platelets, which developed parallel to the (001) Si surface during annealing.

Low temperature diffusion of impurities in hydrogen implanted silicon

The effect of hydrogen implantation on the transport of impurities in silicon is studied. We use secondary ion mass spectrometry measurements to investigate the depth redistribution of oxygen, carbon, and fluorine during low temperature, ≤450 °C, isothermal anneals. Their fast migration toward the projected range region of H implants points to the existence of a strong interaction of the impurities with H-induced defects. Significantly enhanced, as compared to the literature values, diffusivities of the investigated impurities were obtained. The results reveal that hydrogen implantation can be advantageously used for the impurity profile engineering and gettering studies in silicon in the low temperatures annealing regime.

Evolution of Lattice Strain in Hydrogen-Implanted Silicon Prior to Layer Splitting: An X-Ray Scattering Study

We have investigated the effects of hydrogen implantation in silicon wafers by x-ray scattering methods. Different crystalline orientations for the Si single crystals were studied, namely (100), (110) and (111) Si. Large strains normal to the surface were evidenced after implantation, which depends on the Si orientation and can be explained on the basis of the different alignment of the Si-Si bonds with respect to the crystal surface. A comparison with the results from infrared spectroscopy shows that strain is associated to specific H- related point defects, such as monohydride multivacancy and H2*. Finally the evolution of the stressed structure during annealing is discussed.

Effect of hydrogen implantation on semiconductor–metal transition and high-pressure thermopower in Si

In the present work Czochralski-grown silicon single crystals were investigated implanted with different doses of H + ions. The Si wafers were characterized by the Raman scattering technique. Thermoelectric power was studied in a pressure range of 0–20 GPa of p-type Si single crystal wafers containing a thin hydrogenated layer consisting of amorphous Si, nanocrystalline Si and H-rich Si layers. In the region of the pressure-induced phase transition from the initial semiconductor diamond-like into the metal β-Sn lattice, a lowering of thermopower values was noticed in comparison with ones of p-Si.

Effects of hydrogen implantation on the photoluminescence and carrier mobility of ZnO films

A study of the effects of H+ implantation on the photoluminescence (PL) and carrier mobility of ZnO thin films is presented. The 4.2K PL of the as-grown films exhibits free-exciton luminescence at 3.3755eV and strong bound-exciton luminescence between 3.33 and 3.37eV including a peak observed at 3.3313eV which is identified as the collapse of excitons bound to structural defects. While the implantation process results in a slight reduction of the overall PL intensity due to the introduction of nonradiative centers, the intensity of the 3.3313eV bound-exciton peak is reduced by more than two orders of magnitude. We attribute this reduction to preferential interaction of hydrogen with structural defects, such as passivation or the formation of complex defects. Room temperature Hall measurements show that changes in the optical properties of H-implanted ZnO are also accompanied by an increased carrier concentration and decreased carrier mobility.

X-ray scattering study of hydrogen implantation in silicon

The effect of hydrogen implantation in silicon single crystals is studied using high-resolution x-ray scattering. Large strains normal to the sample surface are evidenced after implantation. A simple and direct procedure to extract the strain profile from the scattering data is described. A comparison between different crystallographic orientation of the implanted silicon surface is then presented, namely, for ⟨100⟩, ⟨110⟩, and ⟨111⟩ orientations, showing a dependence that can be related to bond orientation. Effect of annealing on the stressed structure is finally described.

Modification of electrical conductivity in RF magnetron sputtered ZnO films by low-energy hydrogen ion implantation

Abstract The electrical conductivity of ZnO films deposited on Si by the RF sputtering technique were modified by low-energy hydrogen implantation. Hydrogen ions were implanted at 25 keV into various ZnO films with doses ranging from 1 × 1016 to 1.0 × 1017 ions cm−2. High resolution quantitative hydrogen depth profiles of the un-doped and doped samples were measured non-destructively with elastic recoil detection analysis using a finely focussed 2.5 MeV4He+ ion beam impinging onto the samples at 20°. Structural and electrical measurements were carried out on the films by SEM, XRD and Hall probe measurements to explore the effects of hydrogen implantation. It was observed that the electrical conductivity is decreased by as much as an order of magnitude after hydrogen implantation. The films remained polycrystalline after implantation. The results suggest that reducing the n-type conductivity using low-energy hydrogen implantation without annealing may provide a pathway for passivating the donors for a possible subsequent formation of p-type acceptors by ion implantation.

Crystalline quality of bonded silicon-on-insulator characterized by spectroscopic ellipsometry and Raman spectroscopy

The crystalline quality of silicon-on-insulator fabricated by a wafer bonding technique was examined by spectroscopic ellipsometry and Raman spectroscopy. The detailed modeling of the experimental ellipsometric data yields information about structural defects in the silicon-on-insulator layer. The dielectric function of the silicon on insulator that best models the experimental ellipsometric data includes a physical mixture of crystalline silicon and about 4%–7% of amorphous silicon, suggesting a slight lack of long-range order of the silicon atoms in the silicon-on-insulator layer. The use of a dielectric function other than that of pure crystalline silicon is supported by Raman spectroscopic results that indicate the presence of structural defects in the silicon-on-insulator layer. These structural defects may be due to the effects of hydrogen implantation used in the fabrication process of silicon-on-insulator, and∕or the strain imposed by the lattice mismatch between the buried layer and the silicon substrate, and subsequently relaxed under high-temperature annealing.

Hydrogen implantation in InGaNAs studied by spectroscopic ellipsometry

The effects of hydrogen implantation ( E ion∼300 eV, dose∼4.4×10 17 ions/cm 2) on the optical properties of In 0.053Ga 0.947N 0.017As 0.983/GaAs single quantum-wells are studied by spectroscopic ellipsometry and photoluminescence. A strong hydrogen-related blueshift of the quantum-well transition energy is observed by both techniques. After a thermal treatment at 300 °C, the original transition energy is nearly recovered. Optical constants of as-grown and implanted In 0.053Ga 0.947N 0.017As 0.983 quantum-well layers are presented in the near-band gap spectral region (0.75–1.5 eV).

Nickel-silicidation process using hydrogen implantation

The effect of hydrogen implantation on a nickel silicide process has been investigated. X-ray photoemission spectroscopy results show that the hydrogen implantation is effective in suppressing the oxidation of NiSi. It is further shown that the junction leakage current of the implanted samples is about one order of magnitude lower than that of the unimplanted ones.

Mechanical property change and swelling behavior of SiC fiber after light-ion irradiation

Studies on the effects of helium or hydrogen gases on the mechanical properties and size stability of SiC fibers were examined using accelerator implantation techniques. Three types of Nicalon fibers (Nicalon-CG, Hi-Nicalon, and Hi-Nicalon type-S) were examined. Three levels of implanted gas concentrations from 50 to 5000 appm were conducted. Swelling of the fibers was observed after helium implantation. The amount of swelling depended on the helium concentration and the type of fiber. The swelling had vanished after the post-implantation annealing at 1000 °C. The slight decrease of tensile strength was observed after the He implantation. It remained after the post-implantation annealing up to 1400 °C. The significant effects of hydrogen implantation on the strength and swelling were not observed in this work.

Effects of Hydrogen Implantation on the Structural and Electrical Properties of Nickel Silicide

The effects of hydrogen implantation on the structural and electrical properties of nickel silicide have been investigated. Ni films (30 nm) are electron-beam-evaporated on Si substrates, after which plasma immersion ion implantation is used to introduce hydrogen ions into the Ni films at an energy of 350 eV to a dose of For nickel silicidation reactions, rapid thermal annealing is carried out in the range of 400-750°C for 30 s in a nitrogen atmosphere. It is shown that the implanted samples produce lower sheet resistances than the unimplanted samples across the whole annealing temperature range. X-ray diffraction results show that, regardless of the hydrogen implantation, NiSi is transformed into at temperatures in excess of 700°C. X-ray photoemission spectroscopy results show that the hydrogen implantation plays a role in reducing the nickel oxide layer. Compared to the unimplanted samples, the implanted samples exhibit better surfaces and uniform NiSi/Si interface morphologies. Transmission electron microscopy results show that the grain sizes of the implanted sample are smaller than those of the unimplanted sample. It is further shown that the implanted samples are thermally more stable than the unimplanted samples, which is attributed to the difference in the grain sizes of the nickel silicide films. © 2002 The Electrochemical Society. All rights reserved.

Hydrogen Implantation Damage in Polycrystalline Silicon Thin Film Transistors Caused by Ion Doping

The effect of hydrogen implantation into the channel region by ion doping on the characteristics of p-channel polycrystalline silicon (poly-Si) thin film transistors (TFTs) was investigated. To study the hydrogen ion damage in detail, two sets of ion doping conditions, which have different hydrogen profiles with the same boron dose, were adopted to make the source and drain regions of TFTs. Although the boron concentration in both sets of doping conditions is the same, a large difference in the Id–Vg characteristics was observed between the two TFTs. Field effect mobility and threshold voltage deteriorated as the hydrogen dose increased during ion doping. The H2+ ions implanted into the channel region are the dominant influence on the TFT performance. From electron spin resonance (ESR) measurement, the spin density of channel poly-Si was found to increase after ion doping. The hydrogen ions cause defects in the channel region and deteriorate TFT characteristics such as mobility and subthreshold characteristics.