bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Comparison of Low Energy BF2 Implantation in Si and Ge Preamorphized Silicon
Authors: Ruggles Gary A. , Hong Shin-Nam , Wortman Jimmie J. , Ozturk Mehmet , Myers Edward R. , Hren John J. , Fair Richard B. 
Published: March 2011

ABSTRACTLow energy (6 keV) BF2 implantation was carried out using single crystal, Ge-preamorphized, and Si-preamorphized silicon substrates. Implanted substrates were rapid thermal annealed at temperatures from 600°C to 1050'C and boron channeling, diffusion, and activation were studied. Ge and Si preamorphization energies were chosen to produce nearly identical amorphous layer depths as determined by TEM micrographs (approximately 40 nm in both cases).
Boron segregation to the end-of-range damage region was observed for 6 keV BF2 implantation into crystalline silicon, although none was detected in preamorphized substrates. Junction depths as shallow as 50 nm were obtained. In this ultra-low energy regime for ion implantation, boron diffusion was found to be as important as boron channeling in determining the junction depth, and thus, preamorphization does not result in a significant reduction in junction depth. However, the formation of junctions shallower than 100 rmu appears to require RTA temperatures below 1000°C which can lead to incomplete activation unless the substrate has been preamorphized. In the case of preamorphized samples, Hall measurements revealed that nearly complete electrical activation can be obtained for preamorphized samples after a 10 second rapid thermal anneal at temperatures as low as 600°C.
Ion Impiantation Doping of Siox with 31P and 69Ga
Authors: Jones K. S. , Venables D. , Horne C. R. 
Published: March 2011

ABSTRACTImplantations of annealed SIMOX and Si wafers have been done using P and Ga to investigate the effect of excess oxygen and oxygen precipitates on amorphous layer regrowth and category II (end-of-range) dislocation loop elimination. Solid phase epitaxial regrowth of the amorphous silicon in both SIMOX and Si control wafers occurred at 550°C without the formation of category III defects and annealing at 900°C 16 hours resulted in complete removal of the category II defects. In an oxidizing ambient, the implanted SIMOX wafer again exhibited complete defect elimination whereas the Si control wafer showed growth and development of extrinsic stacking faults. It is speculated that the buried oxide may act as a sink for the Si. SIMS results indicate the dopant getters to the Si/SiO2 interfaces and that redistribution can be modelled reasonably well with SUPREME III.
Low-Defect, High-Quality Simox Produced By Multiple Oxygen Implantation with Substoichiometric Total Dose
Authors: Namavar F. , Cortesi E. , Sioshansi P. 
Published: March 2011

ABSTRACTThis work addresses the formation of Separation by IMplantation of OXygen (SIMOX) structures by multiple oxygen implantation into silicon and high temperature annealing. We observed no threading dislocation defects in the several plane view TEM and XTEM micro graphs of each of the samples implanted with a single dose of up to 8 × 1017 0+/cm2. We also demonstrated that with a multiple low-dose (3 to 4 × 1017 0+/cm2) oxygen implantation and high temperature annealing process, we are able to produce continuous and uniform buried SiO2 layers with a total dose of 1.1 × 1018 0+/cm2 (about 60% of the total dose for standard SIMOX). The density of defects is about 105/cm2. There are no silicon islands in the buried layer, no SiO2 precipitates in the silicon top layer, and the Si-SiO2 interfaces are sharp and smooth. SIMOX material with a high-quality Si top layer and a continuous buried layer has been produced with a total dose of 7 × 1017 0+/cm2 (40% of the total dose for standard SIMOX) and a two-step process. However, in this case there are a few Si islands present in the buried SiO2 layer.
On the Structure, Composition, and I–V Characteristics of AL/Ti:W/a-Si Contacts.
Authors: Berger S. , Komem Y. 
Published: March 2011

ABSTRACTThe effect of heat treatments on the microstructure, composition and I–V characteristics of Al/TiW/a-Si contacts was studied.It was found that heat; treatments of the amorophized contacts at the temperature range of 450–520°C led to an interdiffusion of Si atoms into the Al film and of Al atoms into the a-Si region through the Ti:W layer and silicides formation.However, no such interdiffusion and silicides formation could be detected in the contacts made of the unamorphized Si substrate under identical heat treatments.The I–V characteristics of the amorphized contacts are explained by a model of electrical conductivity in amorphous solids.
Atomic Profiles and Electrical Characteristics of Very High Energy (8–20 MeV) Si Implants in GaAs
Authors: Thompson Phillip E. , Dietrich Harry B. , Eridon James M. , Gresko Thomas 
Published: March 2011

ABSTRACTHigh energy Si implantation into GaAs is of interest for the fabrication of fully implanted, monolithic microwave integrated circuits. Atomic concentration profiles of 8, 12, 16, and 20 MeV Si have been measured using SIMS. The range and shape parameters have been determined for each energy. The theoretical atomic concentration profile for 12 MeV Si calculated using TRIM-88 corresponded to the SIMS experimental profile. No redistribution of the Si was observed for either furnace anneal, 825° C, 15 min, or rapid thermal anneal, 1000°C, 10 s. The activation of the Si improved when co-implanted with S. The co-implanted carrier concentration profiles did not show dopant diffusion. Peak carrier concentration of 2×1018/cm3 was obtained with a Si and S dose of 1.5×104/cm2, each.
Self Annealing Implantation of As+ IN SILICON
Authors: Berti M. , Drigo A. V. , Lotti R. , Lulli G. , Merli P. G. 
Published: March 2011

ABSTRACTThe structure of silicon layers implanted with high current As’ beams at different power densities under self-annealing conditions (i.e. with simultaneous damage recovery activated by beam heating) has been investigated with Rutherford Backscattering and Transmission Electron Microscopy techniques. The results have been compared with previous ones obtained with P÷ implantation. They show that, in both cases, an ion-induced mechanism of recrystallization, characterized by an activation energy of the order of 0.3 eV, is operative at temperatures below the values necessary to activate thermal epitaxy. Chemical impurity profiles in samples self-annealed with As+ ions at high beam power density, show the occurrence of two relevant radiation-induced effects: i) diffusion enhancement in the tail region; ii) formation of two impurity peaks, separated by a depletion region centred at the ion projected range. While the deeper peak disappears with increasing irradiation time, the one located at the maximum of nuclear energy loss grows, apparently as a consequence of segregation of As atoms at large clusters of vacancy-type defects.
Analysis of Nitrogen, Boron, and Hydrogen of i-BN Films Fabricated by the Ion Beam Assisted Deposition
Authors: Hirvonen J-P. , Hirvonen J. K. 
Published: March 2011

ABSTRACTThe concentrations of the main constituents of hard i-BN films produced by the ion beam assisted deposition were measured using the nuclear resonance reactions 11B(p,γ) 12C at Ep = 163 keV, and 15N(p,αγ) 12C at Ep = 429 key, respectively. The hydrogen contamination of the samples was investigated using the forward recoil spectroscopy (FRES) technique with a 2 MeV He+ beam. Some complementary analyses of carbon and oxygen were performed using (d,p) and (d,α) -reactions.Hyperstoichiometric boron concentration were found in almost all films. The relative concentrations of nitrogen and boron were also slightly dependent on the deposition conditions as well as the deposition temperature. Contrary to this, hydrogen contamination, that was generally at a low level with few exceptions, was more independent of these parameters.
Lattice Distortion Induced by Laser Assisted MOCVD of GaAs
Authors: Hussien S. A. , Karam N. H. , Bedair S. M. , Fahmy A.A. , El-Masry N. A. 
Published: March 2011

ABSTRACTLaser induced chemical vapor deposition (LCVD) of GaAs has been achieved at low temperature using trimethylgallium and arsine precursors. The deposited film traces the path of the Ar+ laser, thus making it attractive for several applications. The localized thermal expansion resulting from the laser induced temperature rise has to be elastically accomodated in order to prevent lattice distortion during the LCVD process. We report on the growth conditions that can be used without the occurence of plastic deformation in the epitaxial films. A model is presented to explain the thermal expansion induced distortion during the deposition process and will be compared with experimental results.
Argon Ion and Excimer Laser Induced Epitaxy of GaP
Authors: Sudarsan U. , Cody N. W. , Dosluoglu T. , Solanki R. 
Published: March 2011

ABSTRACTLaser-induced epitaxial growth of GaP has been achieved using both pyrolytic and photolytic reactions. A focused beam from an argon ion laser operating at 514.5 nm was used to ‘direct-write’ epitaxial microstructures of GaP on silicon using a pyrolytic process. An ArF excimer laser has also been used to demonstrate homoepitaxy utilizing the photolytic process.
Laser-Induced Chemical Vapor Deposition of Ge-Se Thin Films
Authors: Xiao Tongsan D. , Strutt Peter R. 
Published: March 2011

ABSTRACTThe synthesis of Ge-Se deposits has been demonstrated by using continuous wave CO2laser excited reactions of GeC14and Se2Cl2precursors, each transported in an argon carrier gas. The deposited Ge-Se layers are rich in Ge with a composition of 70% of Ge and 30% of Se. Microstructural examinations reveal that the microstructure consists of amorphous Ge-Se particles ranging in diameter from 2000 Å to 7000 Å. Suggestions are made for the possible mechanisms that might occur during film deposition including, pyrolytic reactions, multiphoton dissociations, and Volmer-Weker film growth.
Synthesis of Diamond Films by Laser-Induced Chemical Vapor Deposition
Authors: Goto Yoshiyuki , Yag Toshinori , Nagai Haruhiko 
Published: March 2011

ABSTRACTAn experimental study of diamond formation by laser-induced chemical vapor deposition (CVD) technique using a gaseous mixture of H2 and CCl4 is reported. The laser used in this work is an ArF excimer laser which emits 80 - 200 mJ pulses with 20 ns duration. We have succeeded in obtaining thin films of diamond by the activation of hydrogen to enhance the removal of graphite and the production of CH radicals. Films obtained without the activation were composed of amorphous carbon and graphite. Hydrogen was activated by a microwave discharge tube or a hot tungsten filament. Films were characterized by Raman scattering and reflection electron diffraction. The diagnostic study using a visible optical emission spectroscope shows that the emission intensity ratio of CH to C2 radicals increases in the system with the activation.
Windowless Wide Area Vuv Lamp for Energy Assisted CVD
Authors: Yu Z. , Sheng T. Y. , Zarnani H. , Collins G. J. 
Published: March 2011

ABSTRACTA ring shaped cold cathode electron gun provides a large area disc shaped vacuum ultraviolet (VUV) light source up to 20 cm in diameter. The windowless disc plasma is also a source of radical and excited atomic gas species. VUV photons, excited species, and radicals can all assist dissociation of CVD feedstock reactants via volume photo-absorption and sensitized atom-molecule collisions, respectively. In addition, the excited radical flux and VUV impingement on the film may also assist heterogeneous surface reactions and increase surface mobility of absorbed species. Thin films of aluminum nitride, Si3N4, and hydrogenated amorphous silicon have been deposited at temperatures between 100°C - 400°C. The deposited films show significant improvement over other photoassisted CVD processes in the film quality achieved, the substrate temperature required and the maximum deposition rates.
Photogenerated Carrier Confinement During the Laser-Controlled Aqueous Etching of GaAs/AlGaAs Nultilayers
Authors: Ruberto M.N. , Willner A.E. , Podlesnik D.V. , Osgood R.M. 
Published: March 2011

ABSTRACTThe sensitivity of the laser-controlled aqueous etching to the optical and electrical properties of semiconductors was utilized during the etching of n-GaAs/n-AlGaAs multilayers to produce novel microstructures. Since this process is controlled by the transport of photogenerated holes to the semiconductor/solution interface, we found that the morphology of etched features is dependent on the bandgap and hole diffusion length of each layer within the heterostructure.
Laser-Induced Atomic Chlorine Etching of Silicon
Authors: Treyz G.V. , Scarmozzino R. , Burke H.H. , Osgood R.M. 
Published: March 2011

ABSTRACTUV laser photolysis of chlorine (λ = 350-360 nm) has been used to produce a microscopic atomic chlorine source. Crystalline silicon has been etched and deep, through-wafer vias have been fabricated. The etching process has been modeled and both theoretical and experimental results are given.
Comparison of CW and Pulsed UV Laser Etching of LiNbO3
Authors: Beeson K.W. , Clements N.S. 
Published: March 2011

ABSTRACTThe results of CW frequency-doubled argon-ion laser etching and pulsed excimer laser etching of lithium niobate (LiNbO3) are compared. Argon-ion laser etching occurs in the presence of Cl2 at laser intensities of 1.1 MW/cm2 or higher. The 257 nm laser beam with up to 25 mW power is focused to a 1.5 μm diameter spot and scanned at speeds of 10 μm/s or less. Excimer laser etching is done at 248 nm (KrF) with the laser beam focused onto the sample with cylindrical optics. Trenches <20 μm wide and several millimeters long are produced by ablating the target and without scanning the beam. Excimer laser etching of lithium niobate has been attempted in the presence of C12, O2, N2, H2 or air. Excellent results are obtained with air as the etching medium.
KrF Laser-Induced Chemical Etching of Nickel with Br2
Authors: Tyndall George W. , Moylan Christopher R. 
Published: March 2011

ABSTRACTA quartz crystal microbalance (QCM) has been used to study the 248 nm laser-induced etching of nickel by Br2. The experiment consists of focusing a pulsed UV laser beam at normal incidence onto the surface of a quartz crystal coated with 1μm of polycrystalline nickel. Absolute etch rates of nickel, in terms of mass removed per unit time, are determined from the integrated sensitivity function of the 6Mhz crystals used in this work. The dependence of the etch rate on Br2 pressure and laser fluence was measured. The kinetic data obtained from these measurements show that the mechanism of the etching process is dominated by the formation and the subsequent removal of a NixBry monolayer.
Ablation of UV-Transparent Materials with Femtosecond UV Excimer Laser Pulses
Authors: Küper S. , Stuke M. 
Published: March 2011

ABSTRACTExperiments on the ablation of undoped polytetrafluoroethylene (teflon), monocrystalline sodium chloride (NaCl) and polymethyl-methacrylate (PMMA) with 300 fs uv excimer laser pulses at 248 nm are reported. In contrast to standard 16 ns excimer laser pulses, these ultrashort pulses ablate essentially uv-transparent materials, heretofore not accessible to clean ablation, with good edge quality and no signs of thermal damage, with removal rates are on the order of one micrometer per pulse.
Excimer Laser Ablation of Sodium Trisilicate Glass
Authors: Eschbach P. A. , Dickinson J. T. , Pederson L. R. 
Published: March 2011

ABSTRACTWe examine effects resulting from the irradiation of glassy sodium trisilicate (Na2O 3SiO2) with 248 nm excimer laser light at fluences from 1–5 J/cm2. We observe a threshold for the onset of etching of the surface at 3 J/cm2. We present SEM images of the resulting surface topography under etching conditions as well as recent measurements of the particle emission and photon emission from atoms leaving the surface region. A clear correlation is observed between this etching threshold and a) onset of emission of fast excited neutrals, as well as b) the appearance of atomic Na D resonance radiation emitted from particles up to several cm from the surface. We also present identifiction of the emitted positive ions.
Laser Physical and Laser Chemical Vapor Deposition of TiN and TiNxOy Films
Authors: Narayan J. , Biunno N. , Srivatsa A.R. , Singh R. , Chen B. 
Published: March 2011

ABSTRACTWe have investigated the formation of polycrystalline TiN and amorphous TiNxOy films using laser physical (LPVD) and laser chemical (LCVD) vapor deposition techniques. The LPVD method involved the ablation of a TiN hot pressed pellet and Ti in the presence of nitrogen plasma using nanosecond XeCl excimer laser pulses (wavelength 308nm, pulse duration 45×10−9 seconds, and energy density ∼4-5 Jcm−2). The films were polycrystalline (average grain size ∼100Å) with face-centered-cubic structure and lattice constant of 4.25Å. The average grain size remained constant as the substrate temperature ranged from 25 to 550°C. In the LCVD method, a pulsed CO2 laser beam was used to crack TiCl4 and NH3 and form TiN films. Amorphous TiNxOy films were formed under poor vacuum conditions in the LPVD techniques. These amorphous TiNxOy films often exhibited explosive recrystallization with characteristic star patterns. Resistivity and microhardness measurements were made on these films and these results have been correlated with microstructure and chemical composition.
Selective—Area Laser Photodeposition of Transparent Conductive SnO2 Films
Authors: Kunz R.R. , Rothschild M. , Ehrlich D. J. 
Published: March 2011

ABSTRACTThe deposition of SnO2 films has been demonstrated using an ArF (193-nm) excimer laser to drive the photochemical reactions of mixed SnCI4 and N2O vapors. Without any annealing, films 100 nm thick grown on room—temperature substrates have resistivities as low as 0.04 Ω—cm. The optical bandgap of 3.20 ev and transmission cutoff wavelength of 330 nm compare favorably with films obtained using alternate higher temperature techniques. The maximum temperature excursion during the 20—ns laser pulse is estimated to be 300 to 400 ºC.
Laser-Induced Multi-Crystallization of Thin Germanium Films
Authors: Ortiz C. , Rubin K.A. , Iuria S. A. 
Published: March 2011

ABSTRACTWe report here the crystallization kinetics of thin (35nm and 60nm) amorphous as-deposited Ge filins using diffraction limited laser beam irradiation and laser pulses between 30ns and IreS. The recrystallization of crystalline as-deposited films was also studied for similar laser conditions. Crystallization was observed for pulses as short as 50ns. We conclude that the use of small beam spots (-1μm) gives a very different crystallization morphology from that observed previously for larger beam diameter and same laser pulse length. In our case for short irradiation times, the nucleation process dominates over crystal growth. Laser irradiation of as-deposited crystalline films produced grains with significantly less defects than grains crystallized from as-deposited amorphous films. Temperature calculations allow us to understand these results by showing that only the small spot irradiation sustains the material at high temperature for times comparable to the pulse width.
The Microstructure of Gold Films Written by Focused Ion Beam Induced Deposition
Authors: Blauner Patricia G. , Ro Jae Sang , Butt Yousaf , Thompson Carl V. , Melngailis John 
Published: March 2011

ABSTRACTFocused ion beam induced deposition of gold microfeatures is accomplished by 40 keV Ga+ bombardment of a substrate on which dimethyl gold hexafluoro acetylacetonate is continuously adsorbed. Under optimum conditions, deposition rates exceeding 11 Å/s have been achieved as well as high aspect ratio features, linewidths of approximately 0.1.μm, and resistivities of 500—1500 μΩcm. The microstructure, composition, and yield of the deposits have been examined as a function of various process parameters. Improved film growth and purity are observed in deposits made with lower organometallic pressures or higher current densities.
Temperature Dependence of Etch Rate and Residual Damage in Reactively Ion Etched GaAs and AlGaAs
Authors: Pearton S. J. , Jones K. S. , Chakabarti U. K. , Emerson B. , Lane E. , Vasile M. J. , Fullowan T. R. , Hobson W. S. , Short K. T. , Haegel N. M. 
Published: March 2011

ABSTRACTThe etch rate of GaAs and AIGaAs during CC12F2:O2 reactive ion etching was measured over the temperature range 50–400ºC. For GaAs, the etch rate increases super-linearly from ∼400Å.min−1 to ∼3000Åmin−1 over this temperature range for a 0.56 W.cm−2, 4 mTorr discharge with a 19:1 CC12F2:O2 mixture. The surface morphology of GaAs undergoes a smooth-to-rough transition near 150ºC, and theresidual damage in the near-surface region appears to decrease with increasing etch temperature. The I-V characteristics of Schottky diodes fabricated on the etched surfaces show ideality factors of 1.001 for 150ºC RIE, although these worsen because of thermal degradation of higher etching temperatures. From AES and XPS data the etched GaAs shows little contamination after etching. In contrast, little temperature dependence of the etch rate of AIGaAs is observed using CC12F2:O2, although once again there is surface degradation for etching temperatures above 150ºC.
Surface Morphological Changes of Polyimide with Oxygen Reactive Ion Beam Etching (RIBE)
Authors: Paik Kyung W. , Ruoff Arthur L. 
Published: March 2011

ABSTRACTAt the beginning of etching, surface asperities appeared on the top plane of the polyimide (PI) film. The formation of surface asperities is due to the ordered phase in PI film. The known dimension of the ordered phase measured by X-ray diffraction is consistant with the size of surface asperities, 100 Å, observed by TEM. Further ion doses made these asperties evolve into smooth bumps which then eroded into cones as a result of etch yield difference as a function of the angle of beam incidence Y(θ)/Y(0) which has a maximum at θ=70. Finally cones led to the development of grass-likestructure on the top plane of the PI film. The formation of platelike structure on the cross-sectional plane of PI indicates that the structural inhomogeniety of the PI film(the ordered and disordered phase) is the main cause for the surface morphological changes of PI.
Electron-Beam Assisted CVD of Silicon Homoepitaxial Films
Authors: West J. P. , Fleddermann C. B. 
Published: March 2011

ABSTRACTThe use of a wide-area electron beam to aid the deposition of epitaxial silicon films has been studied. The electron beam used in this study is generated using a cold cathode, abnormal-glow discharge which allows a wide variation of electron energy and beam current. Depositions are performed on single crystal silicon substrates which are prepared using standard wet chemical silicon cleaning techniques and an in situ plasma etch using nitrogen tri-fluoride diluted in hydrogen. The beam diameter is approximately 10 cm and can readily be scaled up to accommodate larger diameters, allowing great potential for large area single wafer deposition. Using electron beams generated in this system, we have demonstrated enhanced growth rates and improved crystalline quality for films grown withelectronbeam enhancement.
The Initial Stages of Plasma Synthesis of Diamond Films
Authors: Meilunas R. , Wong M.S. , Sheng K. , Ong T.P. , Chang R.P.H. 
Published: March 2011

ABSTRACTThe effects of plasma starting conditions on the initial stages of diamond nucleation and growth in a microwave plasma have been studied as a function of important deposition parameters. The influence of the substrate temperature on the diamond nucleation rate, quality, and final film morphology has been elucidated through various analytical measurements. The diamond films are characterized with Raman spectroscopy, X-ray diffraction, and scanning electron microscopy. Finally, methods are described for reproducibly controlling the grain size and morphology of the diamond films for tribological and abrasive applications.