bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Energy and Dose on Transient-Enhanced Diffusion and Defect Microstructure in Low Energy High Dose As+ Implanted Si
Authors: Krishnamoorthy V. , Venables D. , Moeller K. , Jones K. S. , Freer B. 
Published: September 2012

Abstract(001) CZ silicon wafers were implanted with arsenic (As+) at energies of 10–50keV to doses of 2×1014 to 5×1015/cm2. All implants were amorphizing in nature. The samples were annealed at 700°C for 16hrs. The resultant defect microstructures were analyzed by XTEM and PTEM and the As profiles were analyzed by SIMS. The As profiles showed significantly enhanced diffusion in all of the annealed specimens. The diffusion enhancement was both energy and dose dependent. The lowest dose implant/annealed samples did not show As clustering which translated to a lack of defects at the projected range. At higher doses, however, projected range defects were clearly observed, presumably due to interstitials generated during As clustering. The extent of enhancement in diffusion and its relation to the defect microstructure is explained by a combination of factors including surface recombination of point defects, As precipitation, As clustering and end of range damage.
The Fabrication of High-Speed Electronic Devices by Ion-Beam Synthesis of GexSi1-x Strained Layers
Authors: Elliman R. G. , Jiang H. , Wong W. C. , Kringhøj P. 
Published: September 2012

AbstractGexSi1-x, strained layers can be fabricated by Ge implantation and solid-phase epitaxy and can be used in electronic devices to improve their performance. Several important materials science issues are addressed, including the effect of the strain on solid-phase-epitaxy, the effect of oxidation on the implanted Ge distribution, and the effect of Ge on the oxidation rate of Si. The potential of this process is demonstrated by comparing the performance of metal-oxidesemiconductor field-effect-transistors (MOSFETs) employing ion-beam synthesised GeSi strained layer channel regions with that of Si-only devices.
Germanium Redistribution Phenomena in the Synthesis of SiGe Layers
Authors: Patel C. J. , Butcher J. B. 
Published: September 2012

AbstractA unique germanium redistribution phenomenon occurs in the synthesis of SiGe by 74Ge+ ion implantation. A number of silicon samples were implanted with 74Ge+ ion using a range of substrate temperatures (R.T. to 600°C) with different germanium fluences (1.5 × 1016 cm-2 to 4 × 1016 cm-2) and implantation energies (100keV – 18OKeV). Samples were germanium profiled using Rutherford backscattering spectrometry (RBS) and secondary ion mass spectrometry (SIMS).The experimental results show that the peak range of the germanium implant increases progressively above 150°C and a shift of 40nm in the peak germanium range was measured for a sample implanted at 600°C. The ‘hot’ implants have an extended tail profile contrary to the Debye model for root-mean-square deviations of the lattice atoms from their equilibrium sites which should ideally contribute to dechanneling. The data suggest strongly that dynamic annealing related diffusion (DARD) processes exist, whereby mobile non-equilibrium point defects influence diffusion to take place at the elevated implantation temperature. The SIMS spectra of samples implanted with high Ge fluences at elevated temperature show “uphill” diffusion.
Formation of Buried Layers of (SiC)1-x(AINT)x in 6H-SiC Using Ion-Beam Synthesis
Authors: Yankov R. A. , Hatzopoulos N. , Fukarek W. , Voelskow M. , Heera V. , Pezoldt J. , Skorupa W. 
Published: September 2012

AbstractSolid solutions of SiC and III-V compound semiconductors are recognized as promising materials for novel semiconductor applications. This paper reports on experiments which explore the possibility of synthesizing thin buried layers of (SiC)l-x(AIN)x having composition of about x = 0.2 by co-implanting N+ and Al+ ions into 6H-SiC wafers maintained at temperatures in the range 200 - 800°C. Structural and compositional evaluation of as-implanted samples was carried out using a combination of Rutherford backscattering/channelling spectrometry and infrared reflectance spectroscopy. It is shown that the structures are highly sensitive to the substrate temperature. The use of sufficiently high temperatures (400 - 800°C) enables the crystallinity of the host material as well as relatively low damage levels to be maintained during implantation. The formation of AI-N bonds within the implanted layers is also confirmed over the temperature range studied.
Ion Beam Synthesis of SiC/Si Heterostructures by Mevva Implantation
Authors: Wong S. P. , Ho L. C. , Chen Dihu , Guo W. S. , Yan H. , Kwok R. W. M. 
Published: September 2012

AbstractIon beam synthesis of SiC/Si heterostructures was performed by MEVVA (metal vapor vacuum arc) implantation under various implantation and annealing conditions. The implanted SiC/Si heterostructures were characterized by various techniques. Carbon redistribution in overstoichiometrically implanted samples during annealing to form a stoichiometric SiC layer has been observed for the first time. The FTIR spectra were found to be composed of two components, one attributed to amorphous SiC and the other to β-SiC. It was also found that there are critical dose and critical energy at which the crystalline fraction increases abruptly. Other results on electrical and optical characterization are also presented and discussed
Conductive Tungsten-Based Layers Synthesized by Ion Implantation into 6H-Silicon Carbide
Authors: Weishart H. , Schoneich J. , Voelskow M. , Skorupa W. 
Published: September 2012

AbstractWe studied high dose implantation of tungsten into 6H-silicon carbide in order to synthesize an electrically conductive layer. Implantation was performed at 200 keV with a dose of 1.2x 1017 WIcm 2 at temperatures between 200°C and 400°C. The influence of implantation temperature on the distribution of W in SiC was investigated and compared to results obtained earlier from room temperature (RT) and 500°C implants. Rutherford backscattering spectrometry (RBS) was employed to study the structure and composition of the implanted layers. Implantation at temperatures between RT and 300°C did not influence the depth distribution of C, Si and W. The W depth profile shows a conventional Gaussian shape. Implanting at higher temperatures led to a more confined W rich layer in the SiC. This confinement is explained by Ostwald ripening which is enabled during implantation at temperatures above 300°C. The depth of the implantation induced damage decreases slightly with increasing implantation temperature, except for 400°C implantation. The amount of damage, however, is significantly reduced only for implantation at 500°C.
SiC Precipitate Formation During High Dose Carbon Implantation into Silicon
Authors: Lindner J. K. N. , Volz K. , Stritzker B. 
Published: September 2012

AbstractThe formation of SiC precipitates during the high-dose implantation of carbon ions into Si(100) is studied by means of TEM for implantation conditions, which are suitable for the ion beam synthesis of buried SiC layers in silicon. It is observed that in crystalline silicon nm-sized epitaxially oriented 3C-SiC precipitates are formed which are almost identical in size, nearly independent of the depth and dose (4 - 9 x 1017 C+/cm2 ). With increasing dose, it is mainly the density of precipitates which increases. Amorphization of the silicon host lattice leads to depth intervals with a strongly decreased density of oriented crystalline SiC precipitates. The irradiation induced formatLion of larger randomly oriented SiC crystallites is observed to occur in amorphized regions after prolonged implantation. Both the irradiation induced destruction and formation of SiC precipitates contribute to the generation of a nearly box-shaped precipitate density distribution at doses near the stoichiometry dose.
Quantum Transport in Ion Beam Synthesized Cobalt Disilicide Wires
Authors: Lenssen D. , Mesters S. , Mesters S. 
Published: September 2012

AbstractSubmicrometer cobalt disilicide wires in Si(100) were fabricated by ion beam synthesis. We implanted cobalt ions through the openings of an implant mask made by direct electron beam writing. The formation of the wires was achieved by rapid thermal annealing at temperatures up to 1100°C for 10s. The produced wires have thicknesses of about 85 nm and widths depending on the widths of the implant mask which were varied between 1 μm and 100 nm. These wires were characterized by means of cross-section transmission electron microscopy and magnetoresistance measurements at low temperatures. The results can be well explained by weak localization with strong spirn-orbit scattering and superconducting fluctuation (Maki-Thompson) corrections.
Microstructural Observation of Focused Ion Beam Modification of Ni Silicide/Si Thin Films
Authors: Tanaka Miyoko , Furuya Kazuo , Saito Tetsuya 
Published: September 2012

AbstractFocused ion beam (FIB) irradiation of a thin Ni2Si layer deposited on a Si substrate was carried out and studied using an in-situ transmission electron microscope (in-situ TEM). Square areas on sides of 4 by 4 and 9 by 9 μm were patterned at room temperature with a 25keV Ga+-FIB attached to the TEM. The structural changes of the films indicate a uniform milling; sputtering of the Ni2Si layer and the damage introducing to the Si substrate. Annealing at 673 K results in the change of the Ni2Si layer into an epitaxial NiSi2 layer outside the FIB irradiated area, but several precipitates appear around the treated area. Precipitates was analyzed by energy dispersive X-ray spectroscopy (EDS). Larger amount of Ni than the surrounding matrix was found in precipitates. Selected area diffraction (SAD) patterns of the precipitates and the corresponding dark field images imply the formation of a Ni rich silicide. The relation between the FIB tail and the precipitation is indicated.
Ab Initio Pseudopotential Calculations of Carbon Impurities in SI
Authors: Zhu Jing , Rubia T. Diaz De La , Mailhiot Christian 
Published: September 2012

AbstractAb initio planewave pseudopotential method is used to study carbon diffusion and pairing in crystalline silicon. The calculation is performed with a 40 Ry planewave cutoff and 2×2×2 special k-point sampling with a supercell of 64 atoms. It is found that substitutional carbon attracts interstitial Si forming a <001> C interstitial with a large binding energy of 1.45 eV. The interstitial carbon is mobile and can migrate with a migration energy of 0.5 eV. The interstitial carbon can bind further to another substitutional carbon forming a substitutional carbon-interstitutional carbon pair with a binding energy of 1.0 eV. This model is used to understand the effect of high C concentration on the transient enhanced diffusion in Si.
Synthesis of Soi Materials Using Plasma Immersion Ion Implantation
Authors: Chu Paul K. 
Published: September 2012

AbstractAs the dimensions of integrated circuits shrink towards the deep sub-micromeLer regime, silicon-on-insulator is regarded to be more favorable than silicon substrates. The biggest drawback of SOI is cost which will become more critical for next generation 300-nm silicon wafers. Plasma immersion ion implantation (PIII) provides a viable alternative for the fabrication of SOI wafers as the processing time is very short and independent of wafer size. Pill is being employed to synthesize two types of SOI materials, SPIMOX (Separation by Plasma IMplantation of OXygen) and bonded SOL. In SPIMOX fabrication, both oxygen and water plasmas have been attempted and the results indicate that a discrete buried oxide layer can indeed be formed. In the case of wafer bonding, PIII is utilized for smart-cutting, a process in which implanted hydrogen or helium causes the bonded wafer to crack along the plane thereby making one side of the wafer recyclable. This article reviews the work done and current status of SOI fabrication by PIII.
Thermal Stability of Cu Films on Tin/Ti/Si(100) by Partially Ionized Beam Deposition
Authors: Jang H. G. , Kim K. H. , Choi D. J. , Han S. , Choi S. C. , Choi W. K. , Jung H-J. , Koh S. K. 
Published: September 2012

AbstractCu thin films with a thickness around 850 Å were prepared on Ti45N55/Ti/Si(100) substrates at room temperature by partially ionized beam deposition (PIBD) with an ion energy of 3 keV at pressure of 8×10−7-1 x 10−6 Torr. The Cu/Ti45N55/Ti/Si samples were annealed at 8×10−6-1 × 10−5 Torr with annealing temperature of 500 to 700 °C for 30 min.. Thermal stability of the PIB-Cu films was investigated with Rutherford backscattering spectrometry (RBS), Auger electron spectroscopy (AES), Scanning electron microscopy (SEM), and X-ray diffraction (XRD). The as deposited Cu films had a (111) texture and there was no change of phase in annealed Cu films regardless of annealing temperature. Grain size of the annealed Cu films increased with annealing temperature. SEM studies show no hillock and no voiding on the Cu film surface up to annealing temperature of 700 °C. For PIB-Cu/Ti45N55/Ti/Si samples, all the layers were intact and there was no indication of interdiffusion by conventional depth profiling techniques (RBS, AES) up to 700 °C in vacuum for 30 minutes.
Optical Properties of Multi-Component Cadmium-Silver Nanocluster Composites Formed in Silica by Sequential Ion Implantation
Authors: Zuhr R. A. , Magruder R. H. , Anderson T. S. 
Published: September 2012

AbstractThe formation and optical properties of nanometer dimension metal colloid composites formed by the sequential implantation of Cd then Ag and by single element implantations of Cd and Ag in silica were characterized by transmission electron microscopy (TEM) and optical spectroscopy. A nominal dose of 6×1016 ions/cm2 as determined by current integration was used for both ion species. The doses used for the sequential implantations were a 1 to 1 ratio of Cd to Ag. Sequential implantations of Cd and Ag led to the formation of both multi-component metal nanoclusters and elemental nanoclusters. The electron diffraction measurements indicated that the polycrystalline particles of Ag5Cd8 and elemental Ag were formed. The optical response was consistent with results expected from effective medium theory.
Formation of Silver Metal Nanoclusters in MgO by MeV Ag Implantation
Authors: Ila D. , Wu Z. , Zimmerman R. L. , Sarkisov S. , Qian Y. , Poker D. B. , Hensley D. K. 
Published: September 2012

AbstractNanoclusters of Ag metal in MgO(100) single crystals was formed by implantation of 1.5 MeV silver ions at fluences of 6 x 1016 ion/cm2 and at 1.2 x 1017 ion/cm2, and subsequent annealing at temperatures between 600°C to 1100°C. The formation of the Ag metallic clusters was confirmed using optical absorption spectrophotometry by the absorption band at 430 nm. This is in agreement with the theoretical prediction using Mie's theory, with calculated average nanocluster size about 3 nm. Using ion channeling we confirmed that the orientation of the Ag nanoclusters was in the same direction of the host crystal. Using Z-scan we found the nonlinear refractive index of Ag implanted MgO to be 4.9 x 10-8 esu.
Non-Linear Optical Response of Metallic and Emiconducting Nanocrystals in Fused Silica
Authors: Elliman R. G. , Luther-Davies B. , Samoc M. , Dowd A. 
Published: September 2012

AbstractThe linear and nonlinear optical properties of Ge-implanted fused-silica were examined and compared with Au- and Si-implanted samples. Samples as-implanted with 1.0 MeV Ge ions to a fluence of 3x1017 Ge.cm-2 exhibited relatively large non-linearities, |n2| ≤5x10-12 cm2/W, and fast relaxation times, ∼lps. In contrast, samples implanted with comparable fluences of Au ions exhibited smaller non-linearities, |n2| ∼1x10-13 cm2/W, and slower response times, ≥ 10ps. The non-linearity for Ge was much larger than that for samples as-implanted with Si.
Linear and Nonlinear Optical Properties of Metal Nanoclustersilica Composites Formed by Implantation of Sb in High Purity Silica
Authors: Magruder R. H. , Weeks R. A. , Anderson T. S. , Zuhr R. A. 
Published: September 2012

AbstractThe linear and nonlinear optical properties of a series of Sb nanometer dimension metal colloids in silica were measured. The colloids were fabricated by the implantation of Sb in silica with nominal doses of 3, 6 and 9x1016 ions/cm2 at 320 keV. The linear optical response was measured from 200 to 900 nm. The nonlinear optical properties were measured using the z-scan technique at wavelengths of 596 and 617 nm. The results are compared to linear and nonlinear properties of a sample implanted with 6x1016 Ag ions/cm 2. Both absorption and the nonlinear index of refraction increase with increasing volume fraction for the Sb implanted samples. The lower linear absorption and comparable nonlinear index of refraction for the Sb colloid-glass composites may be better for devices than composites using metal colloids that have a surface plasmon resonance.
Carbon Implanted in Optical Grade Fused Silica: Annealing Effects in Reducing and Oxidizing Atmospheres
Authors: Tung Y. S. , Mu R. , Ueda A. , Henderson D. O. , Wang P. W. , White C. W. , Zhu Jane G. , Zuhr R. A. 
Published: September 2012

AbstractCarbon is implanted into fused silica with doses of 1, 3, 6, 10×1016 ions/cm2. Infrared spectroscopy has identified the formation of CO and CO2 molecules in the implanted glasses. The relationships among concentrations of carbon dioxide, carbon monoxide and carbon doses are established by the infrared measurements. Annealing under different atmospheres have dramatic effects on CO and CO2 concentrations.
Excitation and De-Excitation Processes in Er Implanted Light Emitting Si Devices
Authors: Franzo' G. , Coffa S. , Priolo F. 
Published: September 2012

AbstractIn this paper we show that room temperature electroluminescence at 1.54 μm can be obtained in Er and O co-doped Si diodes, fabricated by ion implantation, under both forward and reverse bias conditions. This electroluminescence is particularly strong under reverse bias at the breakdown, when Er is excited through impact with hot carriers. This last mechanism is shown to occur with a cross section of 6×10-17 cm2. The measured decay lifetime of Er ions during pumping is 100 μs at room temperature and this allows to obtain a high internal quantum efficiency. However, when the diode is shut off, the decay lifetime becomes shorter and in particular it is less than 1.2 μs (that is the time response of our system). These results can be explained by the presence of Auger nonradiative de-excitation processes that are inhibited within the depletion region during pumping and set in when, at the shut off, the Er ions are immediately embedded within the heavily doped region (∼1019/cm3) of the device. The long lifetime (100 μs) during pumping and the very fast decay time (≤ 12 μs) at the diode shut off allow us to obtain, in our diode and under reverse bias, both a high efficiency (> 10-4) and a fast modulation (≥ 80 kHz) of the 1.54 μm emission.
Optical Properties and Surface Roughness of Ion Implanted Single Crystal Sapphire
Authors: Demaree J. D. , Kirkpatrick S. R. , Kirkpatrick A. R. , Hirvonen J. K. 
Published: September 2012

AbstractIt has been shown that metal ion implantation can harden single crystal sapphire and introduce compressive stresses at the surface, which may lead to an increase in the fracture toughness of the material. This may significantly affect the usefulness of this material as a shatter-resistant optical window in missile applications. In this study, we have examined the extent to which sapphire can be implanted without severely degrading its optical quality by ion beam defect production. Optically-polished single-crystal c-axis sapphire was implanted with 150 keV Cr+, Ti+, and Si+ ions to doses of 0.3 – 3.0 × 1017 ions/cm2 at both room temperature and at 800 °C, to measure the optical effect of in situ annealing. Rutherford backscattering spectrometry showed evidence of implant species migration only in the case of Ti implanted at high temperatures; all other implant profiles were Gaussian. The optical transmittance of the sapphire was examined using visible spectrum transmission and Fourier Transform Infrared Spectroscopy. Si implantation resulted in a 10 % reduction in infrared transmittance at the highest ion dose, but this was reduced to 6 % when the implantation was done at high temperature. Both Cr and Ti implantation reduced the sapphire IR transmittance (by 16 % and 42 %, respectively) , but the effect of implantation temperature on transmittance was different. High temperature during implantation increased the transmittance of Cr-implanted samples, but further darkened Ti-implanted samples. Photon tunneling and atomic force microscopy showed that both Ti and Cr implantation roughened the surface of the material.
Violet Luminescence from Ge+-Implanted SiO2 Film on Si Substrate
Authors: Bao Xi-Mao , Gao Ting , Yan Feng , Tong Song 
Published: September 2012

AbstractThe SiO2 films thermally grown on crystalline Si were implanted with Ge ions at 60 keV with doses of l×1015 cm-2 and l×1016 cm-2, followed by thermal annealing at various temperatures. Under an ultraviolet excitation of 240 nm, the films exhibit intense violet luminescence with a peak at 396 nm. This peak is ascribed to the T1 → S0 transition in GeO formed during implantation and annealing. After 1100°C annealing, Ge clusters were formed in an SiO2 matrix and a PL peak at 840 nm, due to the quantum confinement effect, which was measured at low temperature (77 K).
Surface Modification of Polymer by Ion Assisted Reaction in Reactive Gases Environment
Authors: Koh S. K. , Choi S. C. , Choi W. K. , Jung H. J. , Hu H. H. 
Published: September 2012

AbstractWettable surface of polymers (advanced wetting angle ∼10° and surface energy ∼ 60 ∼ 70 erg/cm2) have been accomplished by the ion assisted reaction, in which energetic ions are irradiated on polymer with blowing oxygen gas. The energies of ions are varied from 0.5 to 1.5 keV, doses 1014 to 1017 ions/cm2, and blowing rate of oxygen 0 ∼ 8 ml/min. The wetting angles are increased when the wettable polymers were exposed in air, but are remained in pure water. Improvement of surface energy is mainly due to the polar force. Surface analysis shows hydrophilic functional groups such as C=O, (C=O)-O, C-O, etc., are formed without surface damage after the ion assisted reaction treatment. Comparisons between the conventional surface treatments and the ion assisted reaction are described in term of physical bombardment, surface damage, functional group, and chain mobility in polymer.
Plasma Immersion Ion Implantation Modification of Surface Properties of Polymer Material
Authors: Husein Imad F. , Zhou Yuanzhong , Qin Shu , Chan Chung , Kleiman Jacob I. , Marchev Krassimir 
Published: September 2012

AbstractThe use of plasma immersion ion implantation (PIII) as a novel method for the treatment of polymer surfaces is investigated. The effect of PIII treatment on the coefficient of friction, contact angle modification, and surface energy of silicone and EPDM (ethylene-propylene-diene monomer) rubber are investigated as a function of pulse voltage, treatment time, and gas species. Low energy (0 - 8 keV) and high dose (∼1017 - 1018 ions/cm2) implantation of N2, Ar, and CF4 is performed using an inductively coupled plasma source (ICP) at low pressure (0.2 mTorr). PIII treatment reduces the coefficient of friction (μ) of silicone rubber from μ = 0.464 to the range μ = 0.176 – 0.274, and μ of EPDM rubber decreases from 0.9 to the range μ = 0.27 – 0.416 depending on processing conditions. The contact angle of water and diiodomethylene decreases after implantation and increases at higher doses for both silicone and EPDM rubber.