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862. The production of nuclear targets by a vacuum evaporation
Classified
abstracts
866-867
30 : 18 856. Ion etch technique and its applications. (USA) Ion etching technique utilizes energetic ions in an rf glow discharge to etch away dielectric as well as metallic materials. Similar to conventional wet etching, an etch mask is required which should have a low ion etch rate. In the experiment described the etching is carried out in a vacuum system achieving 5 x lo-* torr, the rf signal ranging from 1.5 to 4.0 watts/cm2 at a fixed frequency of 13.5 MHz. R T C Tsui, Semicond Prod Solid State Technol, 10 (12), 1967, 33-38. 30 857. A survey of vacuum deposition technology. (USA) The advantages and limitations of filament and electron beam evaporation and several variations of sputtering are discussed. The selection of a deposition method requires consideration of a number of factors including the material to be deposited, its interaction with the substrate material, and film thickness tolerances. The measuring and monitoring methods of thickness are reviewed. R H Dudley, Semicond Prod Solid State Technol, 10 (12), 1967, 39-44. 30 858. Advances in rf-induced plasma sputtering. (USA) The sputtering apparatus in its original form is a diode system having a target holder as the cathode and a substrate platform as the anode. In a vacuum of 2 x 1O-2 to 1 x 10-l torr, a potential of about 1000 V ignites a glow discharge. Positive ions of residual gas bombard the target material, ejecting atoms which deposit on the substrate as a film. In the filament-supported discharge system, an operating pressure near 1O-3 torr reduces the possibility of gas inclusions in the film. An external magnetic coil is sometimes used to concentrate the available electrons. The radio frequency-induced plasma sputtering technique eliminates the disadvantages inherent in these two types of systems but retains the advantages of low-pressure operation. Two different configurations are described for exciting free electrons and producing a high degree of ionization. F Kloss and L Herte, SemicondProd SolidState Technol, 10 (12), 1967, 45-49. 30 859. Methods of deposition and physical properties of polycrystalline II-VI films. (USA) Techniques for making polycrystalline films of II-VI compounds on amorphous and polycrystalline substrates are reviewed. The films can be prepared by vacuum deposition using single or multiple evaporation sources or by sputtering. Chemical and spray methods are also described. Many of the physical properties of the layers depend critically on the deposition parameters and on the type of postdeposition processing used. Properties of semiconducting CdS and CdSe films for use in thin film active devices are emphasized. F V Shallcross, RCA Rev, 28 (4), 1967, 569-584. 30 860. Selecting a system for thin film deposition.
(USA) The techniques available for vacuum deposition of thin films, their advantages and disadvantages are presented. The various vacuum evaporation and sputtering techniques are reviewed. D C Anderson, Res Develop, 19 (l), 1968, 42-46. 30 861. A study of spin-wave spectra and surface effects in thin nickel films deposited in ultrahigh vacuum. (USA)
Multiple spin-wave resonances have been observed in thin nickel films deposited on glass substrates held at elevated temperatures. The nickel films used varied in thickness from 50 to 5000 A and were deposited by electron bombardment. The background pressures during deposition were varied from 1 x lo-’ to 4 x lo-lo torr while the substrate temperatures were varied from room temperature to 350°C. W F Chambers, Rep ORO-2430-39, May 1967, 141 pages (Sci Tech Aerospace
Reps, 5 (23), 4328, N67-38384). 30
862. The production of nuclear targets by vacuum evaporation.
(USA) The basic physical principles involved in vacuum evaporation of thin film nuclear targets are reviewed, and methods and techniques of producing such films are surveyed. These include crucibles and evaporation sources, electron bombardment for heating materials, the choice of substrate temperature to produce a homogeneous ductile film, stripping agents, the rates of evaporation and condensation on the substrate, the uniformity of evaporation, and the use of carbon backings for materials which are not easily produced in a selfsupporting film. The usual evaporation techniques for various materials are listed, together with information about crucible yields
and substrate distances. Target packaging methods are considered, and it is reported that the problems involved in shipping have been overcome by packing the targets in a vacuum desiccator which is contained in a specially moulded wood wool packing inside a heavy cardboard box. (Great Britain) G T J Arnison, Rep A WRE-O-32167, May 1967, 42 pages (Sci Tech Aerospace
Reps, 5 (24), 4504, N67-40492).
30 863. A radio frequency dielectric sputtering system with non-grounded electrodes. (Great Britain)
An improved rf dielectric sputtering system is reported in which sputtering from grounded metal components is avoided by using two insulated lead-ins connecting the rf power supply to two metal electrodes backing the dielectric target. One form of the system described consists of a dielectric disc backed by a central disc and an annular electrode. A magnetic field is used to increase the ionization probability and confine the plasma produced by the rf electric field; a separate ionizing source is not used. Results are given for the deposition rate of silica sputtered in argon as a function of rf power input and for the fihn thickness distribution over the work area. Using a silica disc of 20.3 cm diameter with a substrate-to-target distance of 3.2 cm, films could be deposited at a rate of 700 &min in commercial argon at 4 torr pressure. Film thickness uniformity to better than f 5 per cent could be obtained over an area of 200 cm*. L Holland et al, J Sci Zns?rum, (J Phys E), Ser 2, 1 (l), 1968, 32-34. 30 864. Electrical properties of SiO, thin films prepared by evaporation in vacuum. (USSR) The electrical properties and their dependence on the manufacturing process were measured for SiO, thin films with the thickness of 400 to 5,500 8, prepared by evaporation of SiO from a graphite boat at 10-O torr on a substrate with temperature of -100 to +2oo”C. A G Zhdan et al, Radiotekh Russian). 865. Evaporation
Elektron,
13 (2), Feb 1968, 305-315
(in
30 of a larger amount of metal from a tungsten carrier.
(Czechoslovakia) In evaporating metals from a tungsten boat, it is impracticable to melt large amounts of the metal because of shortening the lifetime of the heater. To avoid these disadvantages the following method is proposed: in the gap between two tungsten heated wires a sheet of the metal to be evaporated is inserted so that only the part between wires is melted. The upper part of the material is solid and floats on the melted drop so the melted drop is constant during evaporation and relatively small. Z Jandera, Czech JPhys, A 18 (2). 1968, 222 (in Czech). 30 866. Thin magnetic, conductive or dielectric coatings. (Germany) Coatings are produced at a rate of approximately l-3 A/set by vacuum deposition at a residual gas pressure of about 5 x 10m5torr, optimum in presence of foreign gas, so that the deposited coating material has greater lattice constants than in the bulk form. The process may be used to change saturation magnetisation of magnetic coatings; to produce ferromagnetic coatings from material which is paramagnetic in the bulk state, eg Mn or Cr, or paramagnetic coatings from ferromagnetic material eg Fe or Fe-Ni alloy; to change the electrical conductivity of conductive coatings eg produce Mn coating with high specific resistance, low conductivity being required for low eddy current losses in magnetic storage elements; to produce dielectric coatings from semiconducting material; produce storage elements or elements for micromodular technology. Such a lattice cannot be produced by drawing, since a tension of lo3 kp/mm2 would be necessary and this exceeds any known tensile strength. Telefunken Patentverwertungs GmbH, German Patent 1,259,172, Patent Abstr,
8 (8) part 6, 28th Feb 1968, 4. 30
867. Thin CdSe vapour deposits.
(Germany) Deposits of stoichiometric composition and wurtztite type are obtained by evaporation of Cd and Se and a third substance such as Th or In from three separate sources and deposition in high vacuum onto Se, for the production of Se rectifiers, or on glass or ceramic. The temperature of the Cd and Se vaporizers is a function of the substrate temperature which is 150-220°C. Siemens A G, German Patent 6th March 1968, 3.
1,259,670,
Patent
Abstr,
8 (9) part 6,
abstracts
866-867
30 : 18 856. Ion etch technique and its applications. (USA) Ion etching technique utilizes energetic ions in an rf glow discharge to etch away dielectric as well as metallic materials. Similar to conventional wet etching, an etch mask is required which should have a low ion etch rate. In the experiment described the etching is carried out in a vacuum system achieving 5 x lo-* torr, the rf signal ranging from 1.5 to 4.0 watts/cm2 at a fixed frequency of 13.5 MHz. R T C Tsui, Semicond Prod Solid State Technol, 10 (12), 1967, 33-38. 30 857. A survey of vacuum deposition technology. (USA) The advantages and limitations of filament and electron beam evaporation and several variations of sputtering are discussed. The selection of a deposition method requires consideration of a number of factors including the material to be deposited, its interaction with the substrate material, and film thickness tolerances. The measuring and monitoring methods of thickness are reviewed. R H Dudley, Semicond Prod Solid State Technol, 10 (12), 1967, 39-44. 30 858. Advances in rf-induced plasma sputtering. (USA) The sputtering apparatus in its original form is a diode system having a target holder as the cathode and a substrate platform as the anode. In a vacuum of 2 x 1O-2 to 1 x 10-l torr, a potential of about 1000 V ignites a glow discharge. Positive ions of residual gas bombard the target material, ejecting atoms which deposit on the substrate as a film. In the filament-supported discharge system, an operating pressure near 1O-3 torr reduces the possibility of gas inclusions in the film. An external magnetic coil is sometimes used to concentrate the available electrons. The radio frequency-induced plasma sputtering technique eliminates the disadvantages inherent in these two types of systems but retains the advantages of low-pressure operation. Two different configurations are described for exciting free electrons and producing a high degree of ionization. F Kloss and L Herte, SemicondProd SolidState Technol, 10 (12), 1967, 45-49. 30 859. Methods of deposition and physical properties of polycrystalline II-VI films. (USA) Techniques for making polycrystalline films of II-VI compounds on amorphous and polycrystalline substrates are reviewed. The films can be prepared by vacuum deposition using single or multiple evaporation sources or by sputtering. Chemical and spray methods are also described. Many of the physical properties of the layers depend critically on the deposition parameters and on the type of postdeposition processing used. Properties of semiconducting CdS and CdSe films for use in thin film active devices are emphasized. F V Shallcross, RCA Rev, 28 (4), 1967, 569-584. 30 860. Selecting a system for thin film deposition.
(USA) The techniques available for vacuum deposition of thin films, their advantages and disadvantages are presented. The various vacuum evaporation and sputtering techniques are reviewed. D C Anderson, Res Develop, 19 (l), 1968, 42-46. 30 861. A study of spin-wave spectra and surface effects in thin nickel films deposited in ultrahigh vacuum. (USA)
Multiple spin-wave resonances have been observed in thin nickel films deposited on glass substrates held at elevated temperatures. The nickel films used varied in thickness from 50 to 5000 A and were deposited by electron bombardment. The background pressures during deposition were varied from 1 x lo-’ to 4 x lo-lo torr while the substrate temperatures were varied from room temperature to 350°C. W F Chambers, Rep ORO-2430-39, May 1967, 141 pages (Sci Tech Aerospace
Reps, 5 (23), 4328, N67-38384). 30
862. The production of nuclear targets by vacuum evaporation.
(USA) The basic physical principles involved in vacuum evaporation of thin film nuclear targets are reviewed, and methods and techniques of producing such films are surveyed. These include crucibles and evaporation sources, electron bombardment for heating materials, the choice of substrate temperature to produce a homogeneous ductile film, stripping agents, the rates of evaporation and condensation on the substrate, the uniformity of evaporation, and the use of carbon backings for materials which are not easily produced in a selfsupporting film. The usual evaporation techniques for various materials are listed, together with information about crucible yields
and substrate distances. Target packaging methods are considered, and it is reported that the problems involved in shipping have been overcome by packing the targets in a vacuum desiccator which is contained in a specially moulded wood wool packing inside a heavy cardboard box. (Great Britain) G T J Arnison, Rep A WRE-O-32167, May 1967, 42 pages (Sci Tech Aerospace
Reps, 5 (24), 4504, N67-40492).
30 863. A radio frequency dielectric sputtering system with non-grounded electrodes. (Great Britain)
An improved rf dielectric sputtering system is reported in which sputtering from grounded metal components is avoided by using two insulated lead-ins connecting the rf power supply to two metal electrodes backing the dielectric target. One form of the system described consists of a dielectric disc backed by a central disc and an annular electrode. A magnetic field is used to increase the ionization probability and confine the plasma produced by the rf electric field; a separate ionizing source is not used. Results are given for the deposition rate of silica sputtered in argon as a function of rf power input and for the fihn thickness distribution over the work area. Using a silica disc of 20.3 cm diameter with a substrate-to-target distance of 3.2 cm, films could be deposited at a rate of 700 &min in commercial argon at 4 torr pressure. Film thickness uniformity to better than f 5 per cent could be obtained over an area of 200 cm*. L Holland et al, J Sci Zns?rum, (J Phys E), Ser 2, 1 (l), 1968, 32-34. 30 864. Electrical properties of SiO, thin films prepared by evaporation in vacuum. (USSR) The electrical properties and their dependence on the manufacturing process were measured for SiO, thin films with the thickness of 400 to 5,500 8, prepared by evaporation of SiO from a graphite boat at 10-O torr on a substrate with temperature of -100 to +2oo”C. A G Zhdan et al, Radiotekh Russian). 865. Evaporation
Elektron,
13 (2), Feb 1968, 305-315
(in
30 of a larger amount of metal from a tungsten carrier.
(Czechoslovakia) In evaporating metals from a tungsten boat, it is impracticable to melt large amounts of the metal because of shortening the lifetime of the heater. To avoid these disadvantages the following method is proposed: in the gap between two tungsten heated wires a sheet of the metal to be evaporated is inserted so that only the part between wires is melted. The upper part of the material is solid and floats on the melted drop so the melted drop is constant during evaporation and relatively small. Z Jandera, Czech JPhys, A 18 (2). 1968, 222 (in Czech). 30 866. Thin magnetic, conductive or dielectric coatings. (Germany) Coatings are produced at a rate of approximately l-3 A/set by vacuum deposition at a residual gas pressure of about 5 x 10m5torr, optimum in presence of foreign gas, so that the deposited coating material has greater lattice constants than in the bulk form. The process may be used to change saturation magnetisation of magnetic coatings; to produce ferromagnetic coatings from material which is paramagnetic in the bulk state, eg Mn or Cr, or paramagnetic coatings from ferromagnetic material eg Fe or Fe-Ni alloy; to change the electrical conductivity of conductive coatings eg produce Mn coating with high specific resistance, low conductivity being required for low eddy current losses in magnetic storage elements; to produce dielectric coatings from semiconducting material; produce storage elements or elements for micromodular technology. Such a lattice cannot be produced by drawing, since a tension of lo3 kp/mm2 would be necessary and this exceeds any known tensile strength. Telefunken Patentverwertungs GmbH, German Patent 1,259,172, Patent Abstr,
8 (8) part 6, 28th Feb 1968, 4. 30
867. Thin CdSe vapour deposits.
(Germany) Deposits of stoichiometric composition and wurtztite type are obtained by evaporation of Cd and Se and a third substance such as Th or In from three separate sources and deposition in high vacuum onto Se, for the production of Se rectifiers, or on glass or ceramic. The temperature of the Cd and Se vaporizers is a function of the substrate temperature which is 150-220°C. Siemens A G, German Patent 6th March 1968, 3.
1,259,670,
Patent
Abstr,
8 (9) part 6,