Showing papers on "Evaporation (deposition) published in 1974"

Method of manufacturing thin-film field-emission electron source

Abstract: A method of manufacturing a thin-film field-emission electron source which is of a sandwich structure of a substrate - metallic film-insulating film - metallic film and which has at least one minute cavity and a field-emitter of, for example, a conical shape within the cavity, comprises the steps of (i) forming on a substrate a first layer of metallic film pattern for current supply, (ii) depositing a second layer film made of an electron emissive material onto the entire area of the substrate provided with the first layer, and thereafter subjecting the second layer film to a mesa etch by a photoetching process, to form a conical emitter on the first layer film, (iii) forming a third layer made of an insulating material, the third layer having a height substantially equal to the level of a tip portion of the emitter, (iv) forming a fourth layer of metallic film pattern as an accelerating electrode, and (v) etching the third layer, so as to expose the extremity of the emitter. According to the manufacturing method, a thin-film field-emission electron source can be readily produced merely by the combination between the standard evaporation techniques and etching techniques.

Structure/property relationships in evaporated thick films and bulk coatings

Abstract: This paper reviews the known data on structure/property relationships in thick films or bulk coatings of metals, alloys, and compounds produced by high-rate evaporation/deposition technology. The effects of process variables (depostion temperature and/or kinetic energy of depositing atoms) on the microstructure, texture, and mechanical properties is given. The influence of coatings on corrosion resistance and thermal fatigue is also stated.

Magnetic Properties of Ferromagnetic Metal Alloy Fine Particles Prepared by Evaporation in Inert Gasses. II.

Abstract: Single domain particles of Fe alloys (Fe versus Ni, Cu, Si, Cr, Gd and Ho) were prepared by the evaporation method. The saturation magnetization, remanent magnetization and coercive force of these particles were measured by an automatic magnetic balance. The dispersion of the anisotropy of Fe, Co and Ni particles were determined by a torque meter. The characteristics of these alloy particles were discussed in terms of their applicability to industrial use. The stability for oxydation and the magnetic orientation of particles have already been reported in the previous paper of this series. By choosing a suitable composition of alloys, the coercivity of the prepared particles can be controlled in the range of 200 to 1800 Oe. It was found that the anisotropy dispersion of Fe-Ni alloy was smaller than that of a commercial CrO2 tape.

Growth of indium phosphide films from In and P2 beams in ultra-high vacuum

Abstract: The conditions for the growth of InP films from In and P2 beams in an ultra-high-vacuum environment have been studied. The maximum temperature at which congruent evaporation from an InP (100) surface takes place was found to be 638±10 K, and the restrictions which this limit imposes on the growth conditions are discussed. Stoichiometric InP films have been successfully grown at 573 K.

High-rate evaporation/deposition processes of metals, alloys, and ceramics for vacuum metallurgical applications

Abstract: This is a review on high-rate evaporation/deposition processes for metals, alloys, and ceramics. These processes are described. The influence of process variables on the microstructure and mechanical properties of the deposits is discussed. Present and potential applications are presented.

Epitaxial PbSe and Pb1−xSnxSe: Growth and electrical properties

Abstract: Epitaxial layers of PbSe and Pb1−xSnxSe have been grown on cleaved BaF2 and SrF2 single‐crystal substrates by vacuum deposition of the evaporated binary compounds. The influence of the effusion conditions on the stoichiometry of the molecular beam is considered and it is shown that evaporation of PbSe results in two‐phase layers that contain precipitated lead. Coevaporation of selenium compensated the excess lead and permitted the control of n‐ or p‐type carrier concentrations in epitaxial layers in the range 3×1016−6×1017 cm−3. Structural studies indicate that the layers are single crystals with about the same concentration of low‐angle grain boundaries as observed on the substrates. Low‐temperature Hall mobilities were measured that are as large as those obtained with annealed bulk crystals. The value 4.8×105 cm2/V sec for a PbSe layer with 9.2×1016 hole cm−3 is the largest mobility measured for this material. Below 77°K the mobilities depend markedly on carrier concentration and thermal history of the specimens.

Effects of high nonstoichiometry on EuO properties

Abstract: Electric, magnetic, and electron paramagnetic resonance (EPR) measurements have been performed on thin EuO films prepared either by reactive evaporation of Eu at 400°C or by oxidation of a Eu metal thin film at 200–250°C. The films obtained by reactive evaporation have electrical and magnetic properties very similar to those reported for EuO single crystals of various degrees of nonstoichiometry. The films prepared by oxidation of Eu films at 200–250°C are characterized by a much higher‐valued Curie temperature (Tc≃148 K), while their resistivity is in the range 10−2−1 Ω cm. The EPR signal can be attributed to Eu spins, which shows that in these films there exist fluctuations of Eu doping due to nonstoichiometry. We analyzed the high concentration of oxygen vacancies in the bound magnetic polaron (BMP) model. A high level of defects and oxygen vacancies, inhomogeneously distributed in the film, can account for both their electrical and magnetic properties.

High vacuum ion plating device

Abstract: A DC high tension is impressed between an evaporation source and a holder containing a substrate to be vacuum plated. The source and substrate holder are disposed in an evaporation chamber of high vacuum. Immediately above the evaporation source, an ion chamber is formed and a voltage is impressed between a filament for electron emission and an anode for current collection. The filament and anode are disposed in the ion chamber to transfer an electron shower between them and the evaporation particles which are ionized by the electron shower. When more than one evaporation source is employed, a high frequency coil is disposed in the coexistence region of the ionized evaporated particles generated therefrom, whereby a high frequency oscillation region is formed and thus it becomes possible to effect a chemical bond between ionized evaporated particles of different kinds.

Properties of ZnS Films Evaporated in High Vacuum

Abstract: Thin films of ZnS made by evaporation in high vacuum were investigated by different analytical methods. The changes in chemical composition, crystal structure, texture, density and refractive index of these films are shown as a function of film thickness.

``Photoinduced relaxation'' in amorphous As–S films

Abstract: The photoinduced motion of a As2S8 film‐mica substrate system has been observed during He–Cd laser beam irradiation on the surface of the evaporated region. Experimental results using a prestressed mica substrate during the evaporation show that this phenomenon is a ``photoinduced relaxation'' effect.

Production and Measurement of Dense Metal Ions for Physical Vapor Deposition by a Hollow Cathode Discharge

Abstract: High rate production of metal ions by using an optimum voltage, high current plasma electron beam with metal vapor evaporated from a molten pool is investigated. A focussed electron beam of several ten volts and upto 130 amps strikes an evaporation source at the glancing angle of 45°. Ag is evaporated at a high rate between 0.2 to 2 mTorr of argon and deposited on a substrate. The metal ion density on the substrate is observed separately from residual gas ions and secondary electron emissions from the substrate due to bombardment by photons, ions and metastables. The ratio of the number of the metal ions to the metal atoms, both are striking on the substrate, is measured as a function of the electron beam current, the argon pressure and the applied negative voltage to the substrate. Fraction of the metal ions in the metal species which strikes on the substrate varies from 22 to 40% depending on experimental parameters. Comparison of microscopic structures of the two Ag films deposited by using this plasma evaporation source and by a resistance heating source in a clean high vacuum respectively are presented as a function of substrate temperature during the deposition.

Investigation of hollow cathode effects on the structure of bulk films

Abstract: In a hollow cathode discharge, there is a higher degree of ionization than in the abnormal glow discharge which is characteristic of sputtering and ion plating. A hollow cathode discharge was formed between parallel plates. Metal was evaporated from a source below the hollow cathode and was deposited onto the cathode plates. The pressure–voltage-plate spacing relationship between the cathode plates was related to the deposition efficiency. The grain structure of the deposited metal is reported upon. The evaporation source was a boat-type evaporator. The source metals were copper and silver.

Vacuum evaporation of salt from titanium sponge

Abstract: The rate of salt removal from titanium sponge was determined using a thermogravimetric technique. Both magnesium- and sodium-reduced titanium sponge were used in the investigation. Measurements were made of the rate of salt removal by vacuum evaporation for a range of temperature, bulk density, and sponge surface areas. Removal of magnesium chloride was characterized by the presence of a long period of surface evaporation, or constant-rate drying, during which the major portion of the salt was evaporated. Sodium-reduced sponge showed no such constant-rate period.

Method for monitoring the surface resistivity of metallized film

Abstract: Described herein is a method of monitoring surface resistivity distribution resulting from vacuum deposition of thin, transparent metal films on moving plastic film or other transparent substrates. The process comprises applying to the metallized film electromagnetic radiation and detecting a band width of electromagnetic radiation transmitted through or reflected from the metallized film in the near-infrared region, more particularly within the wavelength range of about 1.5 to 3.0 microns. The detected band width permits excellent correlation between emanant radiation and local conductivity or, reciprocally, resistivity of vacuum deposited gold, silver, and copper. Vacuum deposition can occur, e.g., by vacuum evaporation or sputtering. The metallized films are useful in the production of electrically heated transparent closures such as for automobile windshields.

Method for growing thin epitaxial layers of a non-linear, optically active material

Abstract: Thin film epitaxial layers of mixed oxide compounds, or of solid solutions of two mixed oxides, are deposited on a suitable single crystal substrate. Growth is achieved by introducing the substrate into a crucible containing a saturated solution of the oxide(s) in a molten alkali metal halide having additional undissolved oxide(s) present in the crucible. Evaporation of the alkali metal halide solvent produces and/or maintains the supersaturated condition, which is relieved by epitaxial deposition of the oxide(s) onto the substrate. When two mixed oxides are dissolved in the solvent, the composition of the film is determined and fixed by the temperature of growth. To produce a thin film of a constant composition, growth is conducted isothermally. To produce a thin film with a graded composition throughout its thickness, growth is conducted by slowly cooling the temperature of the solution. Excess, undissolved oxide is kept in a region of the crucible such that the undissolved oxide is several degrees hotter than the liquid in contact with the substrate. This condition results in additional oxide dissolving in the solvent as elsewhere the oxide is being deposited onto the substrate. This method of epitaxial growth provides good control of both the film composition and the film thickness.

Method of reducing the evaporation of Pb during the manufacture of barium titanate (Pb substituted) semiconducting ceramics

Abstract: A method of manufacturing barium titanate semiconducting ceramics having a positive temperature coefficient characteristic of resistivity in which a composite, expressed by a general formula (Ba1 -x -y Pbx Ry) TiO3 (where 0

Investigation of Iron Films by Internal Conversion Electrons Emitted after the Mössbauer Excitation

Abstract: The surface structure of an iron metal film prepared by evaporation in high vacuum was investigated by the measurement of K internal conversion electrons emitted after the Mossbauer excitation. The evaporated sample was annealed in hydrogen gas and put into the vacuum chamber of a β-spectrometer to analyze the momentum of the emitted electrons. The Mossbauer spectra were taken using a 100 mCi 57Co source for various momenta of the electrons, corresponding to various depths of the sample. From these spectra it was found that iron oxide (mainly Fe3O4) existed near the surface of the sample and that the quantity of the iron oxides decreased exponentially with the depth from the surface. Possible applications of the present technique are suggested.

rf bias evaporation (ion plating) of nonmetal thin films

Abstract: The technique of ion plating, which is widely used for the deposition of metallic films, has been successfully applied to the deposition of II–VI compounds by using high-voltage rf instead of dc biasing of the substrate. As a hybrid of evaporation and bias sputtering, this technique retains the advantages while avoiding most of the disadvantages of each. The deposited films have the uniformity and adherence of bias-sputtered films but are deposited as rapidly as evaporated films. The inherent potential of this method for ion implantation has been explored in doping ZnSe up to 1% with P and Li. The resistivity of freshly prepared ZnSe: Li films was of the order of 105–106 Ω cm; however, it increased rapidly upon exposure to light or moisture and made type determination unfeasible.

Evaporator for formation of evaporated layers - with vessel and cover contg openings for passage of evaporated matl

Abstract: Evaporator for prodn. of evaporated layers, esp. of selenium, e.g. for rectifiers and electrophotographic registering materials, has an evaporation vessel, and a sieve-shaped, electrically heated cover that is mechanically and electrically separated from the vessel. The surface area of the cover is sufficient to at least completely cover the evaporation vessel, and its mesh openings have such a width that only the evaporated part of the material can flow through these openings. Evaporated layers formed rapidly, as only a low resistant is offered to the flow of the vapour. Material does not deposit in the mesh openings. No complicated temp. control programmes required. Easily cleaned. Low prodn. and maintenance costs.

Vacuum evaporation plating apparatus

Abstract: A vacuum evaporation plating method and apparatus for suppressing fractional distillation of respective components of a substance to be evaporated comprising a heat source for heating with radiation the evaporating surface of the alloy, and an evaporator having a heat source for heating from either the interior or the bottom of the alloy.

Preparation of new β‐W phases by film‐deposition techniques

Abstract: By sputtering and evaporation simultaneously, β‐W phases Nb3In, Nb3Pb, and Nb3Tl have been prepared. Lattice constants were measured for all samples and found to increase with decreasing substrate temperatures. These values were respectively: 5.303±0.002 A, 5.333±0.005 A, and 5.297±0.005 A. The extended range in producing unstable phases by film‐deposition techniques as opposed to conventional methods is considered.