bluuebunny/crossref_metadata_2025_split huggingface dataset:
Heterogeneous Kinetics of The Chemical Vapor Deposition of Silicon Carbide From Methyltrichlorosilane
Authors: Papasouliotis George D. , Sotirchos Stratis V. 
Published: March 2011

AbstractWe examine the dynamic behavior of a heterogeneous reaction model for the chemical vapor deposition of carbon, silicon, and silicon carbide from the precursors generated by the thermal decomposition of methyltrichlorosilane (MTS, CH3SiCl3 ). All reactions are treated as reversible in order to account for the strong inhibitory effect of the reaction by–products on the deposition process that was observed in our experiments and in other studies. The equilibrium constants of the adsorption steps of the reactions are treated as model parameters, and those of the other reactions are calculated from the thermodynamic constants of a set of overall deposition reactions. Results are presented on the influence of the various model parameters on the reaction rate, the stoichiometry of the deposit, and the variation of these quantities with the distance in a plug flow deposition reactor.
Effect of Oxygen on Diamond Deposition in CH4/O2/H2 Gas Mixtures
Authors: Matsuyama H. , Sato N. , Kawakami H. 
Published: March 2011

AbstractDiamond growth experiments were carried out by a microwave plasma assisted CVD technique in various gas mixtures of CH4(0–100%)/02/H2. The phase diagram obtained by this study shows that a diamond growth region exists. With addition of more than 5% O2 in reactant gases, diamond particles could be included in amorphous or graphitic carbon films even using CH4/O2 gas mixtures. Faceted diamond films were obtained if the oxygen gas concentration [O2] was approximately more than half the methane gas concentration [CH4] ([O2]>[CH4]/2). However, no films were grown when [O2] exceeded half of [CH4] plus 7% ([O2]>[CH4]/2+7%). These results corresponded to the observations by plasma emission spectroscopy. Though oxygen etches carbon films and decomposes methane by forming carbon monoxide, oxygen rarely reacts with hydrogen in a film growth region.
Atomic Layer Growth of SiO2 on Si(100) Using the Sequential Deposition of SiCl4 and H2O
Authors: Sneh Ofer , Wise Michael L. , Okada Lynne A. , Ott Andrew W. , George Steven M. 
Published: March 2011

AbstractThis study explored the surface chemistry and the promise of the binary reaction scheme:(A) Si-OH+SiCl4 → Si-Cl + HCl(B) Si-Cl + H2O → Si-OH + HClfor controlled SiO2 film deposition. In this binary ABAB… sequence, each surface reaction may be self-terminating and ABAB… repetitive cycles may produce layer-by-layer controlled deposition. Using this approach, the growth of SiO2 thin films on Si(100) with atomic layer control was achieved at 600 K with pressures in the 1 to 50 Torr range. The experiments were performed in a small high pressure cell situated in a UHV chamber. This design couples CVD conditions for film growth with a UHV environment for surface analysis using laser-induced thermal desorption (LITD), temperature-programmed desorption (TPD) and Auger electron spectroscopy (AES). The controlled layer-by-layer deposition of SiO2 on Si(100) was demonstrated and optimized using these techniques. A stoichiometric and chlorine-free SiO2 film was also produced as revealed by TPD and AES analysis. SiO2 growth rates of approximately 1 ML of oxygen per AB cycle were obtained at 600 K. These studies demonstrate the methodology of using the combined UHV/high pressure experimental apparatus for optimizing a binary reaction CVD process.
Properties of A New Liquid Organo Gold Compound for MOCVD
Authors: Uchida Hiroto , Saitou Norimichi , Satou Masamitu , Tebakari Masayuki , Ogi Katsumi 
Published: March 2011

AbstractDimethyl(1,1,1,5,5,5-hexafluoroaminopenten-2-onato)Au(III), DMAu(hfap) was found to be very promising compound for CVD Au wiring. It is liquid at r.t. and has high vapor pressure (0.5 Torr at r.t.) and high thermal stability (dec.t. 171°C, δE=25.4Kcal/mol) and can be used as a precursor for MOCVD. CVD gold films were grown on Si(100) from DMAu(hfap) in a quartz vacuum chamber, using thermal activation by an electric heater or photo activation through quartz windows by excimer lasers(XeC1 308nm). A growth rate of 10 nm/min was achieved by thermal activation at 250 °C, (evaporation temperature of 30 °C, H2 flow rate at 100 sccm and chamber pressure of 30 Torr). Resistivities ranged between 2.8 and 5.lμΩ-cm, depending on the film morphology. The growth rate of laser CVD gold films had the tendency of increasing with decreasing the substrate temperature. This phenomenon indicates that photolysis of adsorbed species on the substrate plays an important role in film growth by laser CVD.
Infrared Studies of Ozone-Organosilicon Chemistries for SiO2 Deposition
Authors: Mucha J. A. , Washington J. 
Published: March 2011

AbstractGas-phase Fourier transform infrared spectroscopy has been used to monitor reactants and products in the study of O3 decomposition and the reaction of O3 with tetramethylsilane and tetraethoxysilane. The results confirm the interpretation that O3 decomposition is heterogeneous, and a dominant factor in SiO2 deposition using these chemistries. Product analysis shows that the higher reactivity of TEOS with O3 is probably due to the ability of TEOS to undergo α-hydride elimination of one ethoxy group, per molecule, and one oxidative acetic acid elimination, per molecule, during the deposition process. Results also suggest elimination via the Sicenter involving a single ethoxy group rather than via a 6-center elimination involving two ethoxy groups.
Spectroscopic Investigations of Laser Ablated Germanium Oxide
Authors: Wolf Paul J. , Patterson Brian M. , Witanachchi Sarath 
Published: March 2011

AbstractLaser produced plumes from a GeO2 target were investigated using both optical emission spectroscopy and laser induced fluorescence. Elemental neutral and ionic Ge and diatomic GeO were monitored as a function of O2 pressure at 4 cm from the target surface. Data obtained from laser fluorescence experiments showed no indication of chemical production of GeO in these plumes under any conditions studied; however, the atomic emission intensities of several ionic and neutral Ge lines appeared to increase with O2 pressure. This signified plume interactions with the background gas. The trends in the species concentrations were determined and the results are interpreted with respect to mechanisms for thin film growth.
Indium Tin Oxide Films Formation by Laser Ablation
Authors: Zheng J.P. , Kwok H.S. 
Published: March 2011

AbstractThe electrical and optical properties of room temperature laser deposited indium tin oxide films were studied. It was found that the resistivity of the film was quite sensitive to the deposition conditions. At the optimized conditions, films with a bulk resistivity value of 2.8×10−4 Ω-cm and optical transmission of greater than 90% could be obtained. By using an in situ resistance measurement, it was shown that the initial growth mode was via island formation. Additionally, a classic transition from two- to three-dimensional behavior for the resistance was observed.
Photochemical Modification of Fluorocarbon Resin Surface to Adhere with Epoxy Resin
Authors: Okoshi M. , Miyokawa T. , Kashiura H. , Murahara M. 
Published: March 2011

AbstractAn epoxy-compatible layer was produced in the near-surface region of a fluorocarbon resin by irradiating with an ArF excimer laser in a gaseous B(CH3)3 or a B(OH)3 water solution atmosphere. The pure photochemical reaction was employed in the modification process, the defluorination of the surface was performed with boron atoms which were photo-dissociated from B(CH3)3 or B(OH)3. The CH3 or OH radicals, also photo-dissociated, replaced the fluorine atoms of the surface. As a result, chemical bonding of the surface with the epoxy was performed. The adhesive strength was evaluated by the shearing tensile test, and the epoxy break value of 130 kgf/cm2 was sucessfully achieved.
The Influence of Temperature Gradients on Partial Pressures in a Cvd Reactor
Authors: Oosterlaken T.G.M. , Leusink G.J. , Janssen G.C.A.M. , Radelaar S. , Kuijlaars K.J. , Kleijn C.R. , Van Den Akker H.E.A. 
Published: March 2011

AbstractThe influence of temperature gradients on the partial pressures of a binary mixture in a cold wall low pressure chemical vapor deposition reactor was determined by Raman spectroscopy of the gaseous species in the reactor. It is demonstrated for the first time that the partial pressure of the heavy constituent in the hot region of a low pressure reactor is reduced by 35 % due to the Soret effect. Model calculations that included the Soret effect are in agreement with the experimental data.
Perfect selective Si epitaxial growth realized by synchrotron radiation irradiation during disilane molecular beam epitaxy
Authors: Utsumi Yuichi , Akazawa Housei , Nagase Masao 
Published: March 2011

AbstractPerfect selectivity in Si epitaxial growth on a Si/SiO2 substrate has been achieved by irradiating SR during molecular beam epitaxy (MBE) using disilane. This differs from conventional selective growth by MBE using disilane in that no Si nucleation occurs on SiO2 irrespective of growth time. Temperature above 700°C is necessary for SR -induced selective growth. This perfect selectivity might result from the elimination of adsorbed Si atoms induced by photo-stimulated evaporation of SiO2 which results in the perfect suppression of Si nucleation.
Gate Quality Oxides Prepared by Rapid Thermal Chemical Vapor Deposition
Authors: Kuehn R.T. , Xu X. , Holcombe D.J. , Misra V. , Wortman J.J. , Hauser J.R. , Wang Q.-F. , Maher D.M. 
Published: March 2011

AbstractAs the feature size of MOSFET devices shrink, issues such as thermal budget associated with controlling channel doping profiles and oxide growth kinetics raise concerns about using thermally grown furnace oxides for deep-submicron device applications. To address these concerns, we have developed a new RTCVD oxide process using a gas system of silane and nitrous oxide. The RTCVD oxides are deposited in a lamp-heated, cold wall, RTP system. Deposition rates ranging from 55 Å/min. to 624 Å/min. can be achieved at 800°C with silane nitrous oxide flow rate ratio of 2% and total pressure ranging from 3 to 10 Torr. The results indicate that this RTCVD process can be used to deposit both thin gate and thick isolation insulators for single wafer processing. Deposition rates of the RTCVD oxides exhibit a nonlinear dependence on the total deposition pressure. Electrical characterization of the as-deposited RTCVD oxides shows a mid-gap interface trap density of < 5×1010 eV−1 cm−2 and an average breakdown field of 13MV/cm. AES, RBS and TEM analyses have been used to study surface cleaning effects on the silicon-silicon dioxide interface quality and to determine the chemical composition of the RTCVD oxides. The results show that RTCVD oxides with stoichiometric composition and atomic flat silicon-silicon dioxide interface can be achieved using silane nitrous oxide flow rate ratio of <2%. I-V characteristics and transconductance degradation under hot carrier stress for MOSFET's using as-deposited RTCVD gate oxides have been found to be comparable to those of MOSFET's using thermal gate oxides.
Surface Chemistry of Boron-Doped SiO2 CVD: Enhanced Uptake of Tetraethyl Orthosilicate by Hydroxyl Groups Bonded to Boron
Authors: Bartram Michael E. , Moffat Harry K. 
Published: March 2011

AbstractInsight into how dopants can enhance deposition rates has been obtained by comparing the reactivities of tetraethyl orthosilicate (TEOS, Si(OCH2CH3)4) with silanol and boranol groups on SiO2. This comparison has direct relevance for boron-doped SiO2 film growth from TEOS and trimethyl borate (TMB, B(OCH3)3) sources since boranols and silanols are expected to be present on the surface during the thermal chemical vapor deposition (CVD) process. A silica substrate having coadsorbed deuterated silanols (SiOD) and boranols (BOD) was reacted with TEOS in a cold-wall reactor in the mTorr pressure regime at 1000K. The reactions were followed with Fourier transform infrared spectroscopy. The use of deuterated hydroxyls allowed the consumption of hydroxyls by TEOS chemisorption to be distinguished from the concurrent formation of SiOH and BOH that results from TEOS decomposition at this temperature. It was found that TEOS reacts with BOD at twice the rate observed for SiOD, given equivalent concentrations of BOD and SiOD. This demonstrates that hydroxyl groups bonded to boron increase the rate of TEOS chemisorption. In contrast, additional results show that surface ethoxy groups produced by the chemisorption of TEOS decompose at a slower rate in the presence of TMB decomposition products. Possible dependencies on reactor geometries and other deposition conditions may determine which of these two competing effects will control deposition rates. This has significant implications for microelectronics fabrication since the specific dependencies would be expected to affect process reliability. In addition, this may explain (in part) why the rate enhancement effect is not always observed in boron-doped SiO2 CVD processes.
Hydrogen Pairing on Si(100)-(2×1): A Site-Blocking Study
Authors: Widdra Wolf , Weinberg W. Henry 
Published: March 2011

AbstractThe thermal desorption of hydrogen from a Si(100)-(2×l) monohydride surface has been reported previously to follow first-order kinetics. Pairing of hydrogen atoms on a Si-Si dimer prior to desorption is most likely the cause of this unusual behavior. To examine the degree of hydrogen pairing at various surface temperatures, this study examines the blocking of adsorption sites by hydrogen for subsequent acetylene adsorption. Temperature programmed desorption and Auger electron spectroscopy were used to measure the absolute saturation coverage of acetylene for various coverages of preadsorbed atomic deuterium. The observed linear decrease in saturation coverage of acetylene with deuterium coverage, for atomic deuterium adsorption between 550 and 150 K, indicates that deuterium is paired on Si-Si dimers. The observation that pairing occurs even at 150 K suggests that the diffusion of chemisorbed hydrogen is not responsible for pairing.
Growth of Silicon Films Onto Fluororesin Surface by ArF Excimer Laser
Authors: Miyokawa T. , Okoshi M. , Toyoda K. , Murahara M. 
Published: March 2011

AbstractSilicon films were deposited on a fluororesin surface. The process was divided into two steps: surface modification process and silicon CVD onto the modified parts. In the modification process, SiH4 and B(CH3)3 mixed gases were used with ArF excimer laser. Fluorine atoms of the surface were pulled out by boron atoms which were photo—dissociated from B(CH3)3 and were replaced with silicon atoms released from SiH4. In the CVD process, SiH4 gas was used with high—density excited ArF excimer laser. Silicon films were deposited onto the nuclei by photodecomposition of SiH4.Chemical compositions of the modified layers and the deposited parts were inspected by XPS analysis. 1000 Å thickness of the deposited silicon films was confirmed by the surface roughness interference–meter.
Effect of Post Exposed Hydrogen on Chemisorbed Ethylene on Si(100)-(2×l)
Authors: Widdra Wolf , Huang Chen , Weinberg W. Henry 
Published: March 2011

AbstractThe effect of post adsorbed atomic hydrogen on the adsorption, desorption, and decomposition of ethylene on Si(100)-(2×l) has been studied using high-resolution electron energy loss spectroscopy (HREELS), temperature programmed desorption (TPD), and low-energy electron diffraction (LEED). Exposures to atomic hydrogen of more than 1015 atoms/cm2 convert the initial (2×l) reconstruction of sp3-hybridized, di-σ bonded ethylene to a (l×l) structure. Furthermore, after post exposure to atomic hydrogen, the thermal desorption peak of molecular ethylene is shifted up by approximately 100 K and reduced in intensity. HREEL spectra for deuterated ethylene show the formation of a C-H bond after exposure to atomic hydrogen, whereas the C-C bond remains intact. We explain our data by an atomic hydrogen-driven conversion of the di-σ bonded ethylene to a mono-σ bonded surface ethyl. Thermal activation after post exposure to atomic hydrogen leads to decomposition of about 60% of the initial ethylene in contrast to the observed molecular desorption in the absence of hydrogen.
Deposition and Properties of AlN Films Prepared by Low Pressure CVD with a Metalorganic Precursor
Authors: Cook M. J. , Wu P. K. , Patibandla N. , Hillig W. B. , Hudson J. B. 
Published: March 2011

AbstractAluminum nitride films were deposited on Si (100) and sapphire (1102) substrates by low pressure chemical vapor deposition using the metalorganic precursor trisdimethylaluminum amide, [(CH3)2AlNH2]3. Depositions were carried out in a cold wall reactor with substrate temperatures between 500 and 700 °C and precursor temperatures between 50 and 80 °C. The films were analyzed by X-ray photoelectron spectroscopy, X-ray diffraction, optical microscopy and scanning electron microscopy. The films were generally smooth and adherent with colors ranging from transparent to opaque grey. Cracking and spallation were seen to occur at high film thickness. Deposition rates ranged from 20 to 300 Å/min and increased with both precursor and substrate temperature. Carbon concentrations were small, < 5 at. %, while oxygen concentrations were higher and showed a characteristic profile versus depth in the film. High temperature compatibility testing with sapphire/AlN/MoSi2 samples was carried out to determine film effectiveness as a fiber coating in a composite.
Electrical and Dielectric Characteristics of SrTiO3 Thin Films Grown by PE-MOCVD Technique
Authors: Shi Z. Q. , Chern C. , Liang S. , Lu Y. , Safari A. 
Published: March 2011

AbstractEpitaxial strontium titanate (SrTiO3) thin films have been grown by plasma enhanced metalorganic chemical vapor deposition (PE-MOCVD) technique on different bottom electrode materials, such as Pt/MgO and YBCO/LaAlO3. The as grown SrTiO3 film exhibited an epitaxial structure with <100> orientation perpendicular to the substrates as examined by X-ray diffraction (XRD). The electrical and dielectric properties of the films were investigated by capacitance-voltage (C-V) and current-voltage (I-V) measurements in a temperature range from 80K to 300K. The dielectric constant and dielectric loss were found to be 320 and 0.08 at 100 kHz and room temperature. The dc leakage current density and breakdown voltage were strongly dependent on the choice of the bottom electrode materials. For the films grown on YBCO/LaAlO3, the leakage current density is 8.8×10−7 A/cm2 at 200 kV/cm and the breakdown voltage is about 2.0 MV/cm. These results indicated that the SrTiO3 films are suitable for many devices applications. The frequency dependence of the dielectric constant and dielectric loss were studied in the range of 12 Hz to 1 MHz at room temperature. With the increase of the frequency, the dielectric constant showed a little decrease, while the dielectric loss exhibited a sharp increase which could be attributed to the electrode resistance loss.
Development and Implementation of Large Area, Economical Rotating Disk Reactor Technology for Metalorganic Chemical Vapor Deposition
Authors: Tompa G. S. , Zawadzki P. A. , Mckee M. , Wolak E. , Moy K. , Stall R. A. , Gurary A. , Schumaker N. E. 
Published: March 2011

AbstractThe vertical, high speed, rotating disk reactor (RDR) has, in recent years, found broad application in the Metalorganic Chemical Vapor Deposition of a variety of material systems. These applications include epitaxial films of III-V and II-VI compound semiconductors, oxides (such as YBCO superconductors/ferroelectrics and SiO2, amongst others), Group IV materials (such as diamond and SiC), and metals (such as copper and tungsten). As production of these material systems increases, so too does the need for economical, high yield equipment capable of producing these materials with high levels of uniformity and repeatability. We have used computational fluid dynamic modeling to investigate the complex flow and thermal dynamics required for scaling existing RDRs (as large as a 7.25″ diameter disk handling up to 3×3″ wafers) to larger dimensions (11″ and 12″ diameter disks for multiple 4″ and 15.5″ diameter disk for 3×6″ wafers). The scaling parameters predicted by the modeling codes are reviewed and correlate well with experimental results. Materials results on GaAs films using TBAs, TMGa, and TMA1 for the 11″ diameter system routinely demonstrate within wafer thickness uniformities of <1.1% for 3×4″ wafers, as well as for 6″ or 8″ diameters, wafer to wafer uniformities <1% and run to run repeatabilities within 1%. These results are verified by SEM analysis, as well as with GaAs/AJGaAs Bragg reflectors. The excellent results on the 11″ and 15.5″ diameter platters combined with modeling indicated that 4×4″ wafers on a 12″ diameter platter would produce ideal films which, indeed, is the case. The 11″ diameter results have been surpassed, demonstrating <0.9% for >9″ diameters (4×4″ wafers) on a 12″ diameter susceptor. With high reactant efficiencies (>3 6%), short cycle times between growths using the loadlock, and minimal maintenance requirements, the costs per wafer in a cost of ownership model are found to be dramatically less than in competitive technologies.
Some Considerations of MOCVD for the Preparation of High Tc Thin Films
Authors: Hitchman Michael L. , Shamlian Sarkis H. , Gilliland Douglas D. , Cole-Hamilton David J. , Thompson Simon C. , Cook Stephen L. , Richards Barbara C. 
Published: March 2011

AbstractIn this paper we first give a brief overview of the MOCVD of high temperature superconductors and consider the general requirements of a precursor. We then present results for deposition from Y containing precursors and compare apparent enthalpies of sublimation and deposition activation energies with values in the literature. The problem of Ba containing precursors are briefly reviewed and results given for the sublimation of and deposition from a new stable and volatile precursor. Finally, some comments are made about possible deposition mechanisms.
In Situ Heteroepitaxial Bi2Sr2CaCu2O8 Thin Films Prepared by Metalorganic Chemical Vapor Deposition
Authors: Dimeo Frank , Wessels Bruce W. , Neumayer Deborah A. , Marks Tobin J. , Schindler Jon L. , Kannewurf Carl R. 
Published: March 2011

AbstractBi2Sr2CaCu2O8 thin films have been prepared in situ by low pressure metalorganic chemical vapor deposition using fluorinated β–diketonate precursors. The influence of the growth conditions on the oxide phase stability and impurity phase formation was examined as well as the superconducting properties of the films. Thin films deposited on LaAIO3 substrates were epitaxial as confirmed by x-ray diffraction measurements, including θ-2θ and φ scans. Four probe resistivity measurements showed the films to be superconducting with a maximum Tc0 of 90 K without post annealing. This Tc0 is among the highest reported for thin films of the BSCCO (2212) phase, and approaches reported bulk values.
Deposition of Cerium Dioxide Thin Films on Silicon Substrates by Atomic Layer Epitaxy
Authors: Mölsä Heini , Niinistö Lauri 
Published: March 2011

AbstractCeO2 overlayers up to 360 nm thick were deposited on Si(100) substrates in a flowtype ALE reactor from Ce(thd)4 (thd = 2,2,6,6-tetramethyl-3,5-heptanedione) precursor and ozone. The growth rate was studied as a function of deposition and source temperatures, reactor pressure and pulse durations. The films were characterized for crystallinity, thickness and composition by using XRD, profilometry, XRF, RBS, XPS and SIMS techniques. Films deposited at 375 °C showed a preferential (110) orientation while at 425 °C they were (111) preferentially oriented. Due to the steric hindrance caused by the bulky precursor the growth rate was only 0.4 Å/cycle.