Showing papers on "Nitride published in 1970"

The effect of carbide and nitride additions on the heterogeneous nucleation behavior of liquid iron

Abstract: A systematic study of carbide and nitride additions on the heterogeneous nucleation behavior of supercooled liquid iron was undertaken. It was found that titanium nitride and titanium carbide were very effective in promoting heterogeneous nucleation. These compounds were followed by silicon carbide, zirconium nitride, zirconium carbide, and tungsten carbide in decreasing order of effectiveness. The degree of potency of the nucleation catalysts is explained on the basis of the disregistry between the lattice parameters of the substrate and the nucleating phase. Through the inclusion of planar terms the Turnbull-Vonnegut “linear” disregistry equation was modified to more accurately describe the crystallographic relationship at the interface during heterogeneous nucleation.

Magnetic Properties of the Hexagonal Iron Nitride ϵ‐Fe3.2N

Abstract: The Mossbauer effect has been measured on powder samples of the h.c.p. iron nitride ϵ-Fe3.2N at 295 °K. The measurements indicate, that there are two kinds of Fe-atoms with different environments in this material. This is in accordance with previous X-ray investigations by which it was found that in ϵ-iron nitrides the N-atoms are highly ordered in such a way that e.g. in ϵ-Fe3.2N the Fe-atoms have either one or two N-atoms within their nearest neighbourhood. Furthermore the average magnetic moment of the Fe-atoms in ϵ-Fe3.2N has been measured to be 1.97 μB. Using this value together with the Mossbauer data the magnetic moments of the Fe-atoms are estimated. The moments obtained are 2.4 μB and 1.9 μB respectively. These values are interpreted by similar considerations by which the magnetic structure of the f.c.c. γ′-iron nitride Fe4N has been explained previously in the literature.

Method for manufacturing composite articles containing boron carbide

Abstract: In accordance with the invention, a composite silicon impregnated boron carbide body bonded to a backing material for said body is manufactured by forming a boron carbide powder compact of the desired shape and size, coating a surface of the compact with boron nitride powder, impregnating the boron nitride coated boron carbide powder compact with silicon, removing from the surface of said body at least most of the boron nitride layer and any silicon deposited thereon, and then bonding the silicon impregnated boron carbide body to the organic resin backing material.

Lattice parameters, thermal expansion coefficients and densities of Nb, and of solid solutions Nb–O and Nb–N–O and their defect structure

Abstract: The temperature expansivities (by the X-ray method), the densities and the defect structures of the 3 cubic nonstoichiometric compounds (solid solutions) of the composition Nb, NbO0.017 and NbN0.90O0.013 (nitride) were determined. The lattice parameters a at 25°C were: 3.3004, 3.3047 and 4.3855 A; the linear expansion coefficients, α, between 15 and 65°C were 7.6, 8–65 and 7–75 × 10–6°C−1 respectively. As the temperature is increased, α undergoes several changes in magnitude. The cubic nitride started to decompose at about 850°, with a loss of N (decrease of α). The structure of the oxygen-poor Nb is free from vacancies and interstitial atoms within the limits of error; that of the oxygen-rich Nb contains interstitial atoms on additional sites in a concentration of 1.9%, and the nitride contains vacant sites in both sublattices (4.8% total).

The reaction of nitrogen with titanium between 800 and 1200°C

Abstract: This paper describes phase formation and mass transport during the reaction of iodine-refined titanium with nitrogen at 760 Torr and 800 to 1200°C. Each titanium-nitrogen phase is present within the composition and temperature range of its thermodynamic stability. Between 882 and 1110°C there are the nitrides, TiN and Ti2N, and solutions of nitrogen in α and β-titanium. There is no β-titanium below 882°C or Ti2N above 1110°C. The growth of each phase layer involves some favorably oriented grains from among the many that are nucleated. Nitrogen concentration gradients exist in all phases. Nitrogen is the predominant diffusing species in all phases but a small amount of outward diffusion of titanium occurs through the nitrides, producing α-phase porosity above 1100°C. There is some porosity in the outer regions of TiN. All phases remain mechanically sound and coherent with each other. Changes in the relative proportions of phases during cooling are identified, which enables corrections to be made to kinetic data for the reaction.

Electrical Characteristics of the Silicon Nitride‐Gallium Arsenide Interface

Abstract: The results of an investigation of the electrical characteristics of the silicon nitride‐gallium arsenide interface as determined by capacitance‐voltage (C‐V) curves is presented and discussed. The was pyrolytically deposited from and in the range 650°–750°C on n‐ and p‐type, , . A hysteresis of the C‐V curve is noted; the amount of curve shift is shown to be heavily process dependent. Times involved in curve shift both with and without applied bias are given. Surface state density for the best p sample is in the 1012 range.

Structure and Electrical Properties of Sputtered Films of Hafnium and Hafnium Compounds

Abstract: The electrical properties of 2000–3000‐A‐thick films of hafnium, hafnium nitrides, and hafnium dioxide have been studied. The properties of these films can be related to film structure and composition. Conditions were established under which hafnium films can be prepared by dc sputtering in pure argon with density and resistivity approaching that of pure bulk hafnium. Additions of low concentrations of nitrogen to the argon sputtering atmosphere result in the deposition of films consisting of a solid solution of nitrogen in hafnium. At intermediate nitrogen concentrations films of HfN, a compound with metallic properties, are obtained. Higher nitrogen concentrations in the sputtering atmosphere result in films of nonstoichiometric HfN containing excess nitrogen and finally of films of a higher nitride of hafnium having semiconducting properties. Sputtering in argon‐oxygen mixtures above a critical oxygen concentration results in the deposition of HfO2 films with insulating properties.

Process for producing nitride films

Abstract: Appropriate alkyl derivatives of Group III elements are mixed with ammonia or selected alkyl amines. The mixture and/or product of addition are decomposed at a heated substrate to form a nitride semiconductor film. The invention herein described was made in the course of or under a contract or subcontract thereunder, with Army.

Electronic device with thermally conductive dielectric barrier

Abstract: An electronic device is provided with an active portion which generates heat as a result of internal power losses, such as a semiconductor element, a resistor, a capacitor, etc. The active portion is mounted in thermally conductive relation with a substrate comprised of a unitary layer consisting essentially of aluminum nitride. The aluminum nitride may be in the form of a single crystal or may be polycrystalline.

Preparation of metal nitrides

Abstract: REFRACTORY METAL NITRIDES, SUCH AS ALUMINUM NITRIDE, ARE PRODUCED BY HEATING A MIXTURE OF THE REFRACTORY METAL, CARBON AND A ZINC OR CADMIUM COMPOUND INTHE PRESENCE OF NITROGEN AT A TEMPERATURE OF AT LEAST ABOUT 950*C. THE ZINC OR CADMIUM COMPOUND IS REDUCED TO THE CORRESPONDING ELEMENTAL METAL AND EVAPORATED FROMTHE REACTION MASS TO LEAVE THE DESIRED NITRIDE.

Method for forming a single-layer nitride film or a multi-layer nitrude film on a portion of the whole of the surface of a semiconductor substrate or element

Abstract: The process for preparing an electrically insulating nitride surface coating on a silicon or germanium semiconductor substrate comprising oxidizing the surface of a silicon or germanium semiconductor to form a stain film on said surface; nitriding said oxide stain film surface by heating to a temperature above 600 DEG C in a reactive atmosphere comprising gaseous nitrogen, ammonia or hydrazine and applying ultraviolet light to said surface whereby a chemically and physically stable electrical insulating nitride surfaced semiconductor is formed. The invention also includes a process for preparing a multi-layer nitride surface coating on a silicon or germanium substrate in which the first layer is formed as set forth in the preceding sentence and then one or more additional layers are formed by heating the semiconductor having the aforesaid first layer with a gaseous mixture of (i) a silicon compound selected from the group consisting of silicon halide and silane and (ii) a compound selected from the group consisting of nitrogen, ammonia and hydrazine to form a silicon nitride surface on said nitride surfaced semiconductor. The invention also includes the nitride surfaced semiconductor which may be produced by the foregoing processes.

Analysis of Silicon Nitride Layers on Silicon by Backscattering and Channeling Effect Measurements

Abstract: Backscattering and channeling effect measurements with MeV 4He ions were used to determine the depth dependence of the composition of amorphous silicon nitride layers on single‐crystal silicon. The composition was stoichiometric over the entire layer for high ratios of NH3 to SiH4 used in the deposition reaction at 850°C. For lower ratios, a silicon excess was found, and in extreme cases, the silicon excess was located predominantly near the interface.

The Correlation of Radiation-Hardening with Interstitial Nitrogen Content in Mild Steels

Abstract: The interstitial nitrogen contents of annealed En2, silicon-killed, and aluminium-grain-size-controlled high-manganese mild steels have been determined quantitatively by internal-friction and chemical methods and qualitatively by strain-ageing. Comparison of the results with previously published data on the effects of neutron irradiation on the room-temperature tensile lower yield stresses of the steels shows that the magnitude of the radiation-hardening increased with increasing interstitial nitrogen content. The interstitial nitrogen and the radiation-hardening in the annealed silicon-killed mild steel were decreased by ageing at 650° C (923 K) before irradiation, presumably as a result of the nitrogen in solution combining with the silicon, forming silicon nitride or silicon–manganese nitride. The strain-ageing in the annealed and annealed and aged silicon-killed mild steel was reduced after irradiation, indicating that the interstitial nitrogen was removed from solution. It is tentatively conc...

Gallium nitride formed by vapour deposition and by conversion from gallium arsenide

Abstract: Attempts to prepare single crystal gallium nitride in thin films and bulk form are reported. The thin films were prepared by reacting GaCl3 and NH3 and depositing on to single crystal silicon carbide substrates. The bulk gallium nitride was prepared by the conversion of single crystals of gallium arsenide using an intermediate oxide phase.

Structural properties of vapor deposited silicon nitride

Abstract: Some of the chemical and physical properties of silicon nitride films have been studied to determine the effects of deposition process variables and wafer preparation prior to deposition The boat temperature and the reaction gas mixture were changed to optimize the quality of the silicon nitride films This resulted in amorphous films free of pinholes, cracks, and impurities, together with good electrical properties such as an effective barrier against sodium ions and a low fast and fixed surface state density Most of the work has been done on silicon nitride deposited over silicon dioxide films or silicon dioxide steps on a siliconsubstrate The silane-ammonia and the silicon tetrachloride-ammonia reactions resulted in silicon nitride of comparable physical and chemical properties Cleaning procedures are most effective if they include an etching step to take off 50 to 100A of the oxide prior to nitride deposition The influence of subsequent heat treatments (up to 1200°C) on cracking and etch rates of the silicon nitride films has been studied Films thicker than 2000A deposited over oxide steps were found to crack after heat treatments above 1000°C Films in the lower thickness range of 500 to 1000A are most suitable because they have good resistance against cracking after heat treatments up to 1200°C, do not need excessively long etch times, and are still an excellent barrier against a heavy sodium contamination applied at 535°C

Process for the preparation of vanadium(carbo)nitride

Abstract: A PROCESS FOR THE PREPARATION OF VANADIUM CARBONITRIDE AND/OR VANADIUM NITRIDE-CONTAINING MATERIALS, WHICH CONSISTS IN TREATING AN OXIDIC VANADIUM-CONTAINING MATERIAL AT HIGH TEMPERATURE WITH, IN SUCCESSION, OR WHOLLY OR PARTLY SIMULTANEOUSLY, GASEOUS HYDROCARBONS AND NITROGEN, WITH OR WITHOUT AMMONIA.

Technique for masking silicon nitride during phosphoric acid etching

Abstract: A technique for passivating silicon nitride to phosphoric acid etchants during the formation of semiconductor devices is disclosed. The technique consists of exposing a silicon nitride surface to a diffusion source consisting of either a boron or phosphorous containing source material. The silicon nitride surface is exposed to the diffusion source, at a temperature ranging from 750-1,140* C, for a period of time sufficient to form a diffused source-rich layer of silicon nitride having the desired depth. The source-rich film is then oxidized in a wet oxygen or steam ambient, at a temperature ranging from 8501,100* C, for a period of time sufficient to form a passivating film. The passivating film is immune from attack by phosphoric acid but can be etched with hydrofluoric acid.

Method of securing dense, metal-bonded refractory nitride bodies to steel and product

Abstract: Dense, metal-bonded refractory nitride elements such as cutting edges are secured to metal supports such as steel tool shanks by metallurgically bonding between the two materials a dense, cobalt-bonded tungsten carbide connecting element having an expansion coefficient approximating that of the nitride element.

Spray deposition of silicon powder structures

Abstract: 1,138,284. Silicon and silicon nitride articles. NATIONAL RESEARCH DEVELOPMENT CORP. 31 Jan., 1967 [9 Feb., 1966], No. 5565/66. Heading B5A. [Also in Divisions C1 and C7] Silicon and silicon nitride articles are made by spraying silicon particles on to a preheated former coated with a soluble release agent to form a silicon compact and immersing the former and compact in a solvent to dissolve the release agent and release the compact. The compact may then be dried and heated in an atmosphere of ammonia or nitrogen to convert it to silicon nitride. The silicon is sprayed from a high velocity oxyhydrogen or oxyacetylene flame spray gun and the release agent and solvent are preferably sodium chloride and water respectively. The former may be rotated or reciprocated and the gun moved synchronously with the former to yield an even deposition of powder. The silicon compact may be partially nitrided, machined and then fully converted to the nitride. Articles such as shells, casings, bushes, crucibles, rodomes, heat shields and thermocouple sheaths may be made by this process.

The determination of nitrogen in silicon nitride

Abstract: In the method described for the determination of nitrogen in silicon nitride, the nitride is dissolved in a mixture of hydrofluoric and hydrochloric acids contained in a closed vessel lined with PTFE. After dissolution at 150° C overnight the ammonia formed is steam-distilled from an alkaline solution and determined by titration. The coefficient of variation is about 1 per cent.

立方晶窒化硼素の合成「立方晶窒化硼素の合成に関する研究」 (第1報)

Abstract: This research was carried out on a part of study of synthesis of cubic boron nitride. I part alloy catalyst of Fe3Al, Ag18Cd82 or Ag58Cd42 and 4 parts hexagonal boron nitride were filled up in a platinum tube approximately 4mm in diameter and 8mm long. Three filled methods were used, that is, sandwich type, mixture type of alloy catalyst and hexagonal boron nitride, and bar type of catalyst. The assembly was placed for 30 minutes at maximum about 80kbars and about 2200°C, using a modified girdle type high pressure apparatus. The cubic boron nitride thus formed was isolated from the mixture and was identified by Debye-Scherrer pattern, hardness test and etc.In the case of Fe3Al alloy catalyst, cubic boron nitride with tetrahedron, octahedra and etc., having a zinc-blende struture, could be synthesized over about 1550°C and 45kbar. Its crystal size was about 80μ. The hexagonal boron nitride powder showed an increase in crystal size with increasing temperatures and pressures. The equilibrium line between the hexagonal and cubic forms was located at the extensions of Wentorf's experimental line and the line calculating from thermodynamic data.In the case of Ag18Cd82 and Ag58Cd42 alloys, cubic boron nitride could be obtained over about 1000°C and 32kbar and high yields of it did with increasing temperatures and pressures. The cubic-hexagonal boron nitride equilibrium line was in the same manner as Fe3Al alloy catalyst. Crystal size was about 80 and 150μ, using Ag58Cd42 and Ag18Cd82 alloys, respectively.Alloy of Ag-Cd system was diffused into hexagonal boron nitride at the rate of about 0.10mm/min.

Nitride passivation of mesa transistors by phosphovapox lifting

Abstract: A method of forming a barrier layer impermeable to mobile ions over both the curved and upper plane portions of the principal surface of a mesa-structured semiconductor device. The barrier layer is caused to crack when placed over a special liftant but not when placed over the remainder of the device surface. An etching solution via the cracks then removes the liftant and desired portions of the barrier layer so that electrical contact can be made subsequently to active regions of the device.

Process for purification of refractory metal nitrides

Abstract: Carbon is removed from refractory metal nitrides, such as aluminum nitride, by heating the impure nitride with boric oxide in an atmosphere of nitrogen at a temperature of about 1,200 DEG -2050 DEG C. Boron nitride is formed and provides a valuable mixture of boron nitride and refractory metal nitride.