Showing papers on "Chemical vapor deposition published in 1995"
TL;DR: In this article, thin films of novel superhard composite materials consisting of TiN nanocrystals in an amorphous Si3N4 matrix have been prepared by means of plasma chemical vapor deposition.
Abstract: Thin films of novel superhard composite materials consisting of TiN nanocrystals in an amorphous Si3N4 matrix have been prepared by means of plasma chemical vapor deposition. The films show a high Vickers hardness of 5000 kg/mm2 and elastic modulus of ≳500 GPa, and they are resistant against oxidation in air up to ≥800 °C. The theoretical background of these unusual properties are briefly discussed and practical rules suggested according to which similar properties should be expected for composites of other ternary systems.
482 citations
TL;DR: In this article, a binary reaction for Al2O3 chemical vapor deposition (2Al (CH3)3 + 3H2O → Al 2O3 + 6CH4) was separated into two half-reactions: (A) AlOH + Al(CH 3)3 → Al-O-Al(CH 4)2 + 2H 2O + 2CH4; (B) Al O-Al (H 3)2+ 3H 2
467 citations
TL;DR: In this article, the properties of Ga2O3 thin films deposited by electron-beam evaporation from a high-purity single-crystal Gd3Ga5O12 source are reported.
Abstract: Properties of Ga2O3 thin films deposited by electron‐beam evaporation from a high‐purity single‐crystal Gd3Ga5O12 source are reported. As‐deposited Ga2O3 films are amorphous, stoichiometric, and homogeneous. Excellent uniformity in thickness and refractive index was obtained over a 2 in. wafer. The films maintain their integrity during annealing up to 800 and 1200 °C on GaAs and Si substrates, respectively. Optical properties including refractive index (n=1.84–1.88 at 980 nm wavelength) and band gap (4.4 eV) are close or identical, respectively, to Ga2O3 bulk properties. Reflectivities as low as 10−5 for Ga2O3/GaAs structures and a small absorption coefficient (≊100 cm−1 at 980 nm) were measured. Dielectric properties include a static dielectric constant between 9.9 and 10.2, which is identical to bulk Ga2O3, and electric breakdown fields up to 3.6 MV/cm. The Ga2O3/GaAs interface demonstrated a significantly higher photoluminescence intensity and thus a lower surface recombination velocity as compared to ...
396 citations
Patent•
06 Jun 1995TL;DR: In this article, the authors proposed a method and apparatus for depositing a film on a substrate by plasma-enhanced chemical vapor deposition at temperatures substantially lower than conventional thermal CVD temperatures, which includes placing a substrate within a reaction chamber and exciting a first gas upstream of the substrate to generate activated radicals of the first gas.
Abstract: A method and apparatus for depositing a film on a substrate by plasma-enhanced chemical vapor deposition at temperatures substantially lower than conventional thermal CVD temperatures comprises placing a substrate within a reaction chamber and exciting a first gas upstream of the substrate to generate activated radicals of the first gas. The substrate is rotated within the deposition chamber to create a pumping action which draws the gas mixture of first gas radicals to the substrate surface. A second gas is supplied proximate the substrate to mix with the activated radicals of the first gas and the mixture produces a surface reaction at the substrate to deposit a film. The pumping action draws the gas mixture down to the substrate surface in a laminar flow to reduce recirculation and radical recombination such that a sufficient amount of radicals are available at the substrate surface to take part in the surface reaction. Another method utilizes a gas-dispersing showerhead that is biased with RF energy to form an electrode which generates activated radicals and ions in a concentrated plasma close to the substrate surface. The activated plasma gas radicals and ions utilized in the invention contribute energy to the surface reaction such that the film may be deposited at a substantially lower deposition temperature that is necessary for traditional thermal CVD techniques. Furthermore, the activation of these species reduces the temperature needed to complete the surface reaction. The method is particularly useful in depositing titanium-containing films at low temperatures.
374 citations
TL;DR: The structural evolution of epitaxial GaN layers grown on basal plane sapphire has been studied by atomic force microscopy, x-ray diffraction, and transmission electron microscopy (TEM).
Abstract: The structural evolution of epitaxial GaN layers grown on basal plane sapphire has been studied by atomic force microscopy (AFM), x‐ray diffraction, and transmission electron microscopy (TEM). High‐temperature growth (1050–1080 °C) on optimized nucleation layers leads to clear, specular films. AFM on the as‐grown surface shows evenly spaced monatomic steps indicative of layer by layer growth. AFM measurements show a step termination density of 1.7×108 cm−2 for 5 μm films. This value is in close agreement with TEM measurements of screw and mixed screw‐edge threading dislocation density. The total measured threading dislocation density in the 5 μm films is 7×108 cm−2.
313 citations
TL;DR: In this article, the authors used chemical vapor deposition of benzene and of silicon-containing precursors to obtain graphite and pregraphitic carbons containing nanodispersed silicon.
Abstract: Graphite and pregraphitic carbons are intercalation hosts commonly used in Li ion cells. Using chemical vapor deposition of benzene and of silicon-containing precursors, the authors have prepared carbons containing nanodispersed silicon. The silicon resides within the unorganized regions in the pregraphitic carbons. Materials with up to 11% atomic silicon have been prepared. These materials reversibly react with lithium in electrochemical cells and the reversible specific capacity increases from {approximately}300 mAh/g, in the absence of silicon, to near 500 mAh/g as silicon is added. For silicon content < 6 atomic percent, the reversible capacity increases linearly with a slope of approximately 30 mAh/g per percentage point silicon. This suggests that each silicon atom can reversibly bond with {approximately}1.5 lithium atoms. The increased capacity due to the silicon appears as a broad feature in the differential capacity between 0.1 and 0.6 V vs. Li metal. The large reversible capacities are maintained over many charge/discharge cycles. The carbonaceous matrix provides a pathway for diffusion of Li to the nanodispersed silicon atoms, while it can still intercalate a substantial amount of lithium. Nanodispersions of other lithium alloying atoms in carbon probably can be prepared.
298 citations
TL;DR: In this article, the optical properties of amorphous silicon nitride thin films have been extensively characterized by absorption, photoluminescence (PL), photolumininescence excitation, and electroluminecence measurements, and a simple qualitative model based on nitrogen and silicon dangling bonds adequately explains the observed PL features.
Abstract: Silicon nitride films were deposited at low temperatures (245–370 °C) and high deposition rates (500–1700 A/min) by hot filament assisted chemical vapor deposition (HFCVD). Optical properties of these amorphous silicon nitride thin films have been extensively characterized by absorption, photoluminescence (PL), photoluminescence excitation, and electroluminescence measurements. The optical band gap of the films was varied between 2.43 and 4.74 eV by adjusting the flow rate of the disilane source gas. Three broad peaks at 1.8, 2.4, and 3.0 eV were observed in the PL spectra from these films. A simple qualitative model based on nitrogen and silicon dangling bonds adequately explains the observed PL features. The photoluminescence intensity observed in these films was 8–10 times stronger than films deposited by plasma enhanced chemical vapor deposition, under similar conditions. The high deposition rates obtained by HFCVD is believed to introduce a large number of these optically active defects.
290 citations
Abstract: Diamond samples with varying defect densities have been synthesized by chemical vapor deposition, and their field emission characteristics have been investigated. Vacuum electron field emission measurements indicate that the threshold electric field required to generate sufficient emission current densities for flat panel display applications (≳10 mA/cm2) can be significantly reduced when the diamond is grown so as to contain a substantial number of structural defects. The defective diamond has a Raman spectrum with a broadened peak at 1332 cm−1 with a full width at half maximum (FWHM) of 7–11 cm−1. We establish a strong correlation between the field required for emission and the FWHM of the diamond peak. The threshold fields are typically less than 50 V/μm and can reach as low as 30 V/μm for diamond with a FWHM greater than 8.5 cm−1. It is believed that the defects create additional energy bands within the band gap of diamond and thus contribute electrons for emission at low electric fields.
287 citations
TL;DR: The results indicate that CVD diamond is as biocompatible as titanium (Ti) and 316 stainless steel (SS), and there appears to be less cellular adhesion and activation on the surface of CVD diamonds surfaces compared to Ti and SS.
269 citations
TL;DR: In this paper, a van der Pauw four-probe arrangement was used for measuring the electrical resistivity, which varies between 0.1 × 10 4 and 8.18× 10 4 Ωcm.
264 citations
TL;DR: In this article, the structural properties of amorphous and micro-crystalline silicon films were investigated using Raman spectroscopy, and it was found that a strong relationship exists between the structural order of the silicon matrix and the deposition temperature and deposition rate, and that optimization of the asdeposited silicon microstructure is possible by selecting deposition conditions yielding peak-ratio values in the vicinity of 0.53.
Abstract: In this work we used Raman spectroscopy to investigate the structural characteristics of as‐deposited amorphous and micro‐crystalline silicon films. For amorphous silicon films, the order (or disorder) of the silicon network was quantified using properties of the Raman spectra that were related to key deposition conditions. We found that a strong relationship exists between the structural order of the silicon matrix and the deposition temperature and deposition rate. A quantitative model was proposed relating the intensity ratio of transverse optical phonon peak to longitudinal optical phonon peak to the surface diffusion length, a parameter that was calculated from available data. It was found that optimization of the as‐deposited silicon microstructure is possible by selecting deposition conditions yielding peak–ratio values in the vicinity of 0.53. For as‐deposited micro‐crystalline silicon films, Raman spectroscopy was used to estimate the initial crystalline fraction of the film and monitor the cryst...
TL;DR: In this paper, a tungsten silicide film is deposited from WF6 and SiCl2 H2 onto a substrate, so that the Tungsten to silicon ratio is substantially uniform through the thickness of the WSix film, and the W6 film is substantially free of fluorine.
01 Jan 1995
TL;DR: In this article, the authors present an approach for the analysis of Ferroelectric metal oxide Heterostructures using Pulsed Laser Deposition (PLD) in a multi-component Electroceramic (EC) system.
Abstract: Preface. Pulsed Laser Ablation-Deposition and Characterization of Ferroelectric Metal Oxide Heterostructures R. Ramesh, O. Auciello, V.G. Keramidas, R. Dat. Low Energy Ion Bombardment Induced Effects in Multi-Component Electroceramic Thin Films S.B. Krupanidhi. Growth and Properties of Pb(Mg1/3Nb2/3)O3 - PbTiO3 and Pb(Zr,Ti)O3 Thin Films by Pulsed Laser Deposition A. Safari, C. Tantigate, J. Lee. Wavelength Dependence in Pulsed Laser Deposition of ZnO Thin Films D. Craciun, V. Craciun. Organometallic Chemical Vapor Deposition of Lead Zirconate Titanate M. de Keijser, P.J. van Veldhoven, G.J.M. Dormans. Alkoxide Precursors for Ferroelectric Thin Films M.I. Yanovskaya, N.Ya. Turva, L.I. Solov'Yova. Deposition of Undoped and Doped Pb (Mg,Nb)O3 - PbTiO3, PbZrxTi1-xO3, Alkaline Earth Titanate and Layered Perovskite Thin Films on Pt and Conductive Oxide Electrodes by Spin - On Processing: Correlation of Growth and Electrical Properties M. Klee, U. Mackens, J. Pankert, W. Brand, W. Klee. Relationships between Ferroelectric 90 Degrees Domain Formation and Electrical Properties of Chemically Prepared Pb(Zr,Ti)O3 Thin Films B.A. Tuttle, T.J. Garino, J.A. Voigt, T.J. Headley, D. Dimos, M.O. Eatough. Characterization of Sol-Gel Pb(ZrxTi1-x)O3 Thin Film Capacitors with Hybrid (Pt,RuO2) Electrodes H.N. Al-Shareef, O. Auciello, A.I. Kingon. Organically Modified Sol-Gel Precursors for Ferroelectric Deposition by Spin Coating P. Gaucher, J. Hector, J.C. Kurfiss. Preparation and Properties of Calcium Modified Lead Titanate Thin Films M.L. Calcada, F. Carmona, R. Sirera, B. Jimenez. Microstructure of Lead Titanate-Based Thin Films L. Pardo, J. Ricote, M.L. Calzada. Stoichiometry and Phase Structure of Sol-Gel Derived PZT-Based Thin Films M. Kosec, Y. Huang, E. Sato, A. Bell, N. Setter, G. Dra i , S. Bernik, T. Beltram. Liquid Phase Epitaxy of Na1-yKyTa1-xNbxO3 on KTaO3 Substrates Z. Sitar, R. Gutmann, P. Gunter. Pulse Switching Characterization of Ferroelectric Thin Films P.K. Larsen, R. Cuppens, G.J.M. Dormans. Polarization, Conduction, and Breakdown in Non-Ferroelectric Perovskite Thin Films R. Waser. Anomalous Logarithmic Dependencies in CD.C. Breakdown of Ferroelectric Thin Films J.F. Scott. The Shape of the Hysteresis Curve of Ferroelectric Single Crystals and Ceramics G. Arlt. Fast Transient Measurements on Electroceramic Thin Films G.W. Dietz, M. Schumacher, R. Waser. The Influence of Dopants on the Leakage Current in PZT Thin-Film Ferroelectric Capacitors D.J. Wouters, G. Willems, G. Groeseneken, H.E. Maes, K. Brooks, R. Klissurska. Photo-Induced Storage and Imprinting in (Pb,La)(Zr,Ti)O3 Thin Films D. Dimos, W.L. Warren, B.A. Tuttle. Depletion, Depolarizing Effects and Switching in Ferroelectric Thin Films A.K. Tagantsev, M. Landivar, E. Colla, K.G. Brooks, N. Setter. Nonstoichiometry, Defects, and Charge Transport in PZT M.V. Raymond, D.M. Smyth. X-Ray Diffraction Line Profile Analysis of ZnO Thin Films Deposited on Al-SiO2-Si Substrates P. Sutta, Q. Jackuliak, V. Tvarozec, I. Novotny. Electron Emission from Ferroelectrics H. Gundel. Integration of Ferroelectric Thin Films for Memory Applications H. Achard, H. Mace. Processing and Device Issues of High Permittivity Materials from Drams B.E. Gnade, S.R. Summerfelt, D
Patent•
TSMC1
TL;DR: In this paper, a gap filling and self-planarizing silicon oxide insulator spacer layer within a patterned integrated circuit (PIIC) layer is proposed to fill the gap in the IC.
Abstract: A method for forming a gap-filling and self-planarizing silicon oxide insulator spacer layer within a patterned integrated circuit layer. Formed upon a semiconductor substrate is a patterned integrated circuit layer which is structured with a titanium nitride upper-most layer. The patterned integrated circuit layer also has at least one lower-lying layer formed of a material having a growth rate with respect to ozone assisted Chemical Vapor Deposited (CVD) silicon oxide layers greater than the growth rate of ozone assisted Chemical Vapor Deposited (CVD) silicon oxide layers upon titanium nitride. Formed within and upon the patterned integrated circuit layer is a silicon oxide insulator spacer layer deposited through an ozone assisted Chemical Vapor Deposition (CVD) process. The silicon oxide insulator spacer layer is formed until the surface of the titanium nitride upper-most layer is passivated with the silicon oxide insulator spacer layer. The silicon oxide insulator spacer layer is then etched from the surface of the titanium nitride upper-most layer. Finally, additional portions of the silicon oxide insulator spacer layer are sequentially deposited and etched until the surface of the silicon oxide insulator spacer layer over the lower layer(s) of the patterned integrated circuit layer is planar with the upper surface of the titanium nitride upper-most layer of the patterned integrated circuit layer.
TL;DR: In this paper, the structure of GaN epilayers on (0001) SiC substrates has been studied using x-ray diffraction and transmission microscopy, and the defect structure of the GaN film away from the substrate consists mostly of threading dislocations with a density of ∼109 cm−2.
Abstract: The crystalline structure of GaN epilayers on (0001) SiC substrates has been studied using x‐ray diffraction and transmission microscopy. The films were grown by metalorganic chemical vapor deposition, using AlN buffer layers. X‐ray diffraction measurements show negligible strain in the epilayer, and a long‐range variation in orientation. Transmission electron lattice images show that the AlN buffer layer consists of small crystallites. The nature of the buffer layer and its interfaces with the substrate and the GaN film is discussed. The defect structure of the GaN film away from the substrate consists mostly of threading dislocations with a density of ∼109 cm−2.
Patent•
13 Dec 1995TL;DR: In this paper, a process for depositing tungsten metal on a silicon surface with the deposited layer having improved uniformity of thickness over prior art deposition techniques is described. But the process involves the steps of removing any native silicon dioxide present on the silicon surface, forming a barrier layer which overlies the silicon surfaces, which prevents the upward diffusion of silicon atoms from the polycrystalline surface, and depositing a final tengsten metal layer on top of the barrier layer.
Abstract: This invention is a process for depositing tungsten metal on a silicon surface with the deposited layer having improved uniformity of thickness over prior art deposition techniques. The process involves the steps of removing any native silicon dioxide present on the silicon surface, forming a barrier layer which overlies the silicon surface which prevents the upward diffusion of silicon atoms from the polycrystalline surface, and depositing a final tungsten metal layer on top of the barrier layer. The barrier layer is preferably a refractory metal nitride. It may be formed directly by chemical vapor deposition, by reactive sputtering, or it may be formed indirectly by depositing a preliminary tungsten metal layer, subjecting the preliminary layer to a plasma formed from NH3 and N2 gases. Both preliminary and final tungsten metal layers are deposited preferably via chemical vapor deposition using the WF6 and SiH4 as reactants.
TL;DR: In this article, the Ni particles were prepared by annealing Ni thin film deposited on quartz glass substrates and the size of the Ni particle was controlled by the thickness of Ni film.
Abstract: Chemical vapor deposition using 2‐methyl‐1,2′‐naphthyl ketone as a starting material has been done between 1000 and 600 °C on Ni particles with diameters ranging from 10 to 500 nm. The Ni particles were prepared by annealing Ni thin film deposited on quartz glass substrates. The size of the Ni particle was controlled by the thickness of the Ni film. Carbon nanotubes were obtained at 700 °C when the diameter of the Ni particles was about 20–30 nm.
TL;DR: In this article, a review of the chemical vapor deposition (CVD) of metals is presented, where metal-containing compounds are being synthesized as new precursors, and the results from CVD experiments can be used to assist in the development of new CVD precursor.
Abstract: The chemical vapor deposition (CVD) of metals is a rapidly developing area in which metal-containing compounds are being synthesized as new precursors. This article reviews this area and discusses precursor design, reaction pathways, reactor types, and the influence of reactor operating conditions on film growth. We have gathered recent results for precursor design and CVD chemistry and show how analysis of results from CVD experiments can be used to assist in the development of new CVD precursors.
TL;DR: In this paper, the growth of high quality AlN and GaN thin films on basal plane sapphire, (100), and (111) silicon substrates using low pressure metalorganic chemical vapor deposition X-ray rocking curve linewidths of about 100 and 30 arcsec were obtained.
Abstract: The growth of high quality AlN and GaN thin films on basal plane sapphire, (100), and (111) silicon substrates is reported using low pressure metalorganic chemical vapor deposition X‐ray rocking curve linewidths of about 100 and 30 arcsec were obtained for AlN and GaN on sapphire, respectively Room‐temperature optical transmission and photoluminescence (of GaN) measurements confirmed the high quality of the films The luminescence at 300 and 77 K of the GaN films grown on basal plane sapphire, (100), and (111) silicon was compared
Patent•
NEC1
TL;DR: In this article, a plasma-enhanced CVD process for depositing a silicon oxide film on a substrate by using an organosilicon compound such as tetraethoxysilane and oxygen or ozone as the essential reactants is described.
Abstract: The subject is a plasma-enhanced CVD process for depositing a silicon oxide film on a substrate by using an organosilicon compound such as tetraethoxysilane and oxygen or ozone as the essential reactants. The disclosed CVD method uses a plasma containing oxygen ions, and the density of oxygen ions impinging on the substrate surface is cyclically decreased and increased with a short period such as, e.g., 1 sec. In extreme cases which are rather preferable, the effect of the oxygen plasma is cyclically nullified and returned to a maximum to thereby alternate plasma CVD and plain thermal CVD. The obtained film is comparable in film properties to silicon oxide films deposited by known plasma CVD methods and, when the substrate has steps such as aluminum wiring lines, is better in step coverage and gap filling capability. The film exhibits a still better profile when hydrogen peroxide gas or an alternative hydrogen containing gas is added to the reactant gas mixture.
TL;DR: In this paper, a series of boron-doped polycrystalline diamond films were studied with Raman and infrared (IR) absorption spectroscopy, and the appearance of the Fano line shape was correlated with the disappearance of discrete electronic transitions of the acceptor observed in the IR spectrum and the shift of the broadened peak to lower energy.
Abstract: A series of boron‐doped polycrystalline diamond films grown by direct current and microwave plasma deposition was studied with Raman and infrared (IR) absorption spectroscopy. A Fano line shape is observed in the Raman spectra for films with a boron concentration in a narrow range near 1021 cm−3. The appearance of the Fano line shape is correlated with the disappearance of discrete electronic transitions of the boron acceptor observed in the IR spectrum and the shift of the broadened peak to lower energy. The Fano interaction is attributed to a quantum mechanical interference between the Raman phonon (0.165 eV) and transitions from the broadened impurity band to continuum states composed of excited acceptor and valence band states.
TL;DR: In this article, the role of defects in the electron emission from undoped or p-type doped diamond and indicate that the improved emission characteristics of as-implanted diamond is due to the defects created by the ion implantation process.
Abstract: Diamond films and islands grown by chemical vapor deposition were implanted with boron, sodium, and carbon ions at doses of 1014–1015/cm2. This structural modification at the subsurface resulted in a significant reduction of the electric field required for electron emission. The threshold field for producing a current density of 10 mA/cm2 can be as low as 42 V/μm for the as‐implanted diamond compared to 164 V/μm for the high quality p‐type diamond. When the ion‐implanted samples were annealed at high temperatures in order to anneal out the implantation‐induced defects, the low‐field electron emission capability of diamond disappeared. These results further confirm our earlier findings about the role of defects in the electron emission from undoped or p‐type doped diamond and indicate that the improved emission characteristics of as‐implanted diamond is due to the defects created by the ion implantation process.
TL;DR: In this article, cyclic voltammetry and ac impedance analysis were used to measure the background current response and capacitance of interfaces formed at as grown (untreated) boron-doped polycrystalline diamond thin-film electrodes in contact with aqueous electrolytes.
Abstract: Cyclic voltammetry and ac impedance analysis were used to measure the background current response and capacitance of interfaces formed at as grown (untreated) boron-doped polycrystalline diamond thin-film electrodes in contact with aqueous electrolytes. The diamond films (∼1 cm 2 , 15 μm thick ; carrier concentration, ∼10 17 cm -3 ) were grown on conducting Si substrates by plasma-enhanced chemical vapor deposition. Cyclic voltammetry was also used to determine the charge transfer reactions of several redox analytes at as grown and chemically wet etched diamond thin-film electrodes and to study the effect of surface pretreatment, including Fe(CN) 6 3-/4- , IrCl 6 2-/3- , Ru(NH 3 ) 6 3+/2+ , dopamine, 4-methylcatechol, MV 2+/+/0 , and ferrocene. The electrochemical response exhibited by the films is explained using two models : (i) traditional electron transfer at a p-type semiconductor-electrolyte interface and (ii) electron transfer at a composite electrode composed of nondiamond carbon impurities contained within a diamond matrix such that k° nondiamond >> k° diamond.
TL;DR: In this paper, PbTiO3 films were prepared by metalorganic chemical-vapor deposition on MgO(001) and LaAlO3 (001) oriented substrates, and the defect structure of the films, including grain tilting, threading dislocation density and 90° domain formation, was strongly dependent on the choice of substrate material.
Abstract: Epitaxial PbTiO3 films were prepared by metalorganic chemical‐vapor deposition on MgO(001)‐, SrTiO3(001)‐, and LaAlO3(001)‐oriented substrates. Four‐circle x‐ray diffraction, transmission electron microscopy, Rutherford backscattering (RBS) channeling, and optical waveguiding were performed to characterize the deposited films. Epitaxial, single‐crystal films were obtained on all three substrate materials under the same growth conditions. However, the defect structure of the films, including grain tilting, threading dislocation density, and 90° domain formation, was strongly dependent on the choice of substrate material. Films grown on MgO(001) and LaAlO3(001) (pseudocubic indices) substrates are nominally c‐axis oriented; however, the PbTiO3 grains in the film form a fourfold domain structure, with the grains tilted ∼0.6° and ∼0.7°, respectively, toward the [100] directions (cubic or pseudo‐cubic) of the substrates. In addition, these films contain a significant volume fraction of 90°‐domain (a‐axis) stru...
TL;DR: In this article, self-assembled monolayers (SAMs) of alkylsiloxanes were patterned by microcontact printing (μCP) on a number of substrates: N/Al 2 O 2, Si/SiO 2, TiN/TiO 2, glasses, indium tin oxide (ITO), and plasma modified polyimide.
Abstract: Self-assembled monolayers (SAMs) of alkylsiloxanes were patterned by microcontact printing (μCP) on a number of substrates : N/Al 2 O 2 , Si/SiO 2 , TiN/TiO 2 , glasses, indium tin oxide (ITO), and plasma-modified polyimide. The patterned SAMs on these surfaces define and direct the selective chemical vapor deposition (CVD) of copper using (hexafluoroacetylacetonato)(vinyltrimethylsilane)copper(I) (Cu I (hfac)(vtms)) as the source gas. This paper presents several examples of microstructures of copper fabricated by selective, SAM-directed CVD, including fabrication of thin-film interconnects (with feature sizes of 0.5-100 μm), and selective filling of trenches and vias (models of microstructures having high aspect ratios) with feature sizes below 1 μm.
TL;DR: In this paper, the Schottky barrier heights of Pt and Pd on n-type GaN films were derived and compared with those of Au and Ti in previous reports.
Abstract: Schottky barriers on n‐type GaN films grown by low‐pressure metalorganic chemical vapor deposition are characterized and derived. A thin Pt or a Pd layer is deposited by electron‐gun evaporation to form Schottky contacts in a vacuum below 1×10−6 Torr. The Schottky barrier heights of Pt on the n‐GaN film are determined to be 1.04 and 1.03 eV by current–voltage (C–V) and current density–temperature (J–T) measurements, respectively. Also based on C–V and J–T measurements, the measured barrier height of Pd on n‐GaN is 0.94 and 0.91 eV, respectively. Schottky characteristics of Pt and Pd observed in the experiment are compared with those of Au and Ti in previous reports.
TL;DR: In this paper, an epitaxial growth of aluminum nitride thin films on Si(111) substrates has been demonstrated by pulsed laser ablation of sintered AlN target.
Abstract: Aluminum nitride thin films have been grown epitaxially on Si(111) substrates, for the first time, by pulsed laser ablation of sintered AlN target. The influence of process parameters such as laser energy density, substrate temperature, pulse repetition rate, nitrogen partial pressure, etc. on epitaxial growth has been investigated to obtain high quality AlN films. These films were characterized by Fourier transform infrared spectroscopy, Raman spectroscopy, x‐ray diffraction (Θ and ω scans) technique, high resolution transmission electron microscopy, and scanning electron microscopy. The films deposited at laser energy density in the range of 2–3 J/cm2, substrate temperature of 750 °C, and base pressure of 3×10−7 Torr are single phase and highly oriented along c axis normal to the Si(111) planes. The results of x‐ray diffraction and electron microscopy on these films clearly show the epitaxial growth of the AlN films with an orientational relationship of AlN[0001] ∥ Si[111] and AlN[2110] ∥ Si[011]. Th...
TL;DR: In this article, a blue-violet gallium nitride (GaN) light emitting p−n junctions were grown by the method of electron cyclotron resonance assisted molecular beam epitaxy.
Abstract: Blue‐violet gallium nitride (GaN) light emitting p‐n junctions were grown by the method of electron cyclotron resonance‐assisted molecular beam epitaxy. This method has been modified to minimize plasma induced defects. Contrary to similar devices grown by metalorganic chemical vapor deposition, these devices do not require any postgrowth annealing to activate the Mg acceptors in the p layer. These devices turn‐on at approximately 3 V and have a spectral emission peaking at 430 nm.
TL;DR: In this paper, the effects of deliberate hydrogenation of GaN were investigated for heteroepitaxial layers grown by metalorganic chemical vapor deposition, and the GaN layers were either Mg−doped, p−type after thermal activation, or Si−dopted, n type.
Abstract: The effects of the deliberate hydrogenation of GaN were investigated for heteroepitaxial layers grown by metalorganic chemical vapor deposition. The GaN layers were either Mg‐doped, p‐type after thermal activation, or Si‐doped, n type. Elemental depth profiles from secondary ion mass spectroscopy reveal a striking contrast after a deuteration at 600 °C: the deuterium concentration in Mg‐doped GaN is ∼1019 cm−3 while there is no detectable deuterium incorporation in the n‐type material. Variable temperature Hall effect measurements provide the most direct evidence to date for Mg–H complex formation with the decrease in the hole concentration upon hydrogenation accompanied by an increase in the hole Hall mobility.
TL;DR: In this paper, carbon nitride thin films have been successfully grown on nickel substrates by a novel arc-plasma jet chemical vapor deposition (APJVD) and characterized by Auger electron spectroscopy, transmission electron microscopy, and Raman spectrographs.
Abstract: Carbon nitride thin films have been successfully grown on nickel substrates by a novel arc‐plasma jet chemical vapor deposition. These films were characterized by Auger electron spectroscopy, transmission electron microscopy, and Raman spectroscopy. Small grains (∼0.1 μm) as well as nanocrystallites found in the films were identified to be β‐C3N4. Raman spectroscopy also confirmed the existence of β‐C3N4 phase in the films through five pronounced Raman bands as expected from the Hooke’s law approximation based on the vibrational frequencies obtained in analogous compound, β‐Si3N4.