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1857. Silicon-gold potential barriers made by localized sputtering method
Classified abstracts 1852-1882 physical and electrical properties of the deposited material. Particular investigations determined: dielectric constant; loss factor; voltage breakdown strength; surface properties using the MOS technique; and material properties by monitoring infrared absorption, chemical etch rate and film growth rate. R C G Swann et al, J Electrochem Sot, 114 (i’), July 1967, 714-717. 30 1852. Sputtering.
(USA) Alloy targets were sputtered to determine the amount of sputtering required to reach equilibrium conditions, where material is removed in the same proportions as the bulk. In alloys of 55 per cent Cu and 45 per cent Ni and of 90 per cent Ni and 10 per cent Ti, it appears that an equivalent of 10-20 atomic layers must be removed before equilibrium conditions are reached at bombarding ion energies of 500-1000 eV. Experiments with simultaneous sputtering of two targets having widely different yields are discussed. G S Anderson et al, Rep AD-643920, 1966 (L&on Systems Inc, Minneapolis,
Minnesota).
1853. Sputtering intermediates on titanium electrodeposited chromium. (USA)
to improve
adhesion
30 of
Intermediate layers of chromium, nickel and/or iron have been sputtered on titanium substrates. In the latter cases, upon subsequent chromium electrodeposition, adhesion was localized and nonuniform. Chromium electrodeposits on chromium intermediate-sputtered layers, however, were uniform and adherent as indicated by bend tests. F X Hassion, chusetts).
Rep SA-TR18-1097,
1966 (Springfield
Armory,
30
films by cathodic sputtering. (USA) For values of x varying from 0.05 to 0.15, these films were sputtered on to single crystal substrates of sodium chloride, germanium and sapphire. The resultant films were amorphous but became crystalline on annealing. Optical transmission and electron probe analysis showed a slightly lower mercury concentration in the film than in the source material. Although cadmium telluride sputtered films are possible in polycrystalline form, it was not found possible to obtain films of sputtered mercury telluride. The vacuum chamber used was evacuated to 1OW torr and back-filled with oxygen-free argon. After several such cycles the system was evacuated to 10e6 torr and the pressure adjusted by increasing the argon pressure using a micrometer valve. The use of oxygen-free argon as discharge gas enhanced the disintegration rate of the source material and prevented undesirable reactions between the sputtered deposit and the residual gas. Sot, 114 (6), June 1967,616619.
1855. Tantalum oxide films prepared by oxygen plasma and reactive sputtering. (USA)
30 anodization
The processes of glow discharge anodization and dc diode reactive sputtering were investigated for the formation of tantalum oxide films for thin-film capacitors. The dc reactive sputtering was carried out at a cathode potential of 4 kV and in an argon pressure of 30 mtorr. At this potential, it was found that the deposition rate of tantalum oxide (in &min) could be expressed as : 6x 1O-3 divided by the oxygen partial pressure in the oxygen-argon gas mixture (for the pressure range of oxygen from 8 x 1O-6 to 1 x 1O-2 torr, and an electrode spacing 10 cm). The gas phase anodization was carried out at a cathode potential of 1 kV and a pressure of 50 mtorr of oxygen. For this purpose a tantalum film deposited by sputtering in pure argon was used. Dielectrics up to a maximum thickness of 3000 8, could be prepared by these methods. The first method (dc reactive sputtering) produces thickness variations over 50 cmB of 4 to 20 per cent compared with the second method (glow discharge) which gave variations of 4 to 1 per cent. F Vratny, J Am Ceram Sot, 50 (6), June 1967,283-287. 30 1856. On using the method of cathode sputtering for the preparation of semiconducting compound thin films. (Czechoslovakia)
Equipment is described for preparing TnSb thin films by cathode sputtering. The dependence between the film thickness and electrical characteristics on sputtering parameters is stated. Since, in a glow discharge, no decomposition into free components will take place, the suitability for preparing other compound thin films by this method is discussed. J Cervenak,
Slabopr
Obzor,
28 (7), July 1967, 442-447
barriers
made
by localized
(in Czech).
30 sputtering
A device is described for the fabrication of fast diodes. Si-Au potential barriers are produced by the following method: on a Si plate a layer of SiO, is produced and a metal foil mask with a hole is attached. Then SiO, is removed under argon at 1O-3 torr by ionic etching, localized to the holes at the mask, Subsequently the apparatus is evacuated and Au film is evaporated through the same mask. In this way, Si-Au contacts with diameters as small as 100 microns have been made. Z Majewski, Bull Acad Polon Sci Sir Sci Tech, 15 (4), 1967, 343-346 (in English). 30 1858. Vacuum processes for the deposition of thin films.
(Germany) The similarities and characteristic differences of evaporation and condensation processes in high vacuum evaporation, cathodic sputtering, and plasma sputtering are explained. Applications of these techniques and the associated vacuum systems are described. Cathodic sputtering is considered as most suitable for the deposition of “high-boiling” materials, at rates of up to 10 &sec on small surfaces. High vacuum evaporation can be used for the de osition of most elements and compounds, at rates of 10e-lo3 1 /sec. The applications of these techniques include a very large field from microcircuits to plating of plastics and metals. KG Gunther, Chem Zng Tech, 39 (ll), June 1967,641~648 (in German).
Massa-
1854. Cd,Hg,,Te
H Kraus et al, J Electrochem
1857. Silicon-gold potential method. (Poland)
1859. Process for the vapour deposition (USA) radiation of the substrate.
of material
30 without thermal
The process consists of separating the vapour waves coming from the vapour source from the accompanying heat waves, by decomposing both types of waves simultaneously into impulses of definite length. The more rapid and therefore preceding heat wave impulses are caught by a moving screen system, while the relatively slower vapour wave impulses are allowed to pass through unhindered. A F Horn and A F Aldrian, US Patent 3,333,982, Patent Ofice, 841 (l), 1st Aug 1967, 230.
Official Gaz US
30 (USA) 1860. Reduction of oxides by ion bombardment. The deposition of a metal coating on a surface of an oxide body, such as barium titanate, copper oxide, iron oxide, silicon oxide, tantalum oxide and titanium oxide, comprises mounting the oxide body and a piece of metal within the chamber. Argon, helium, krypton, mercury, neon or xenon can be fed into the chamber for ionisation. A radio frequency signal is applied to the oxide body for bombarding and selectively removing oxygen from the surface. The bombarded surface is then coated with particles from the metal. Litton O&e,
Systems Inc, US Patent 3,336,211, 841 (3), 15th Aug 1967, 921.
Oficial
Gaz
US Patent
30
1861. Metal-film production. (Great Britain) Suitable for producing a thin metallic film on a substrate by vacuum deposition, a number of substrates are caused to be tumbled together while being subjected to the metal vapour under the required conditions of heat and vacuum, the proximity of the source of metal vapour to the overall volumetric space occupied by the substrates while they are being tumbled being variable to permit control of this process. In a preferred procedure, the specified volumetric space is shielded from the metal-vapour source, and the vapour is only permitted to reach the space via a special access area of variable predeterminable dimensions. American Components Inc, Brit Patent 1,074,901, Patent Abstr, 7 (30) part 5, 28th July 1967. 30
(Great Britain) Capacitors having stable capacitance, low dissipation factors and stable temperature coefficient for use in microminiaturized circuits are made by building up alternate layers of metal and vapourdeposited void-free poly-p-xylylene film. Films of at least 100 8, may be deposited on gold, silver, copper, aluminium, lead or selenium foil or wire with a bulk resistivity less than 100 and preferably less than 10 pohm cm. The resulting capacitors are self-healing in that any electrical breakdown or arcing may be removed by burning through 1862. Thin film capacitors.
623
(USA) Alloy targets were sputtered to determine the amount of sputtering required to reach equilibrium conditions, where material is removed in the same proportions as the bulk. In alloys of 55 per cent Cu and 45 per cent Ni and of 90 per cent Ni and 10 per cent Ti, it appears that an equivalent of 10-20 atomic layers must be removed before equilibrium conditions are reached at bombarding ion energies of 500-1000 eV. Experiments with simultaneous sputtering of two targets having widely different yields are discussed. G S Anderson et al, Rep AD-643920, 1966 (L&on Systems Inc, Minneapolis,
Minnesota).
1853. Sputtering intermediates on titanium electrodeposited chromium. (USA)
to improve
adhesion
30 of
Intermediate layers of chromium, nickel and/or iron have been sputtered on titanium substrates. In the latter cases, upon subsequent chromium electrodeposition, adhesion was localized and nonuniform. Chromium electrodeposits on chromium intermediate-sputtered layers, however, were uniform and adherent as indicated by bend tests. F X Hassion, chusetts).
Rep SA-TR18-1097,
1966 (Springfield
Armory,
30
films by cathodic sputtering. (USA) For values of x varying from 0.05 to 0.15, these films were sputtered on to single crystal substrates of sodium chloride, germanium and sapphire. The resultant films were amorphous but became crystalline on annealing. Optical transmission and electron probe analysis showed a slightly lower mercury concentration in the film than in the source material. Although cadmium telluride sputtered films are possible in polycrystalline form, it was not found possible to obtain films of sputtered mercury telluride. The vacuum chamber used was evacuated to 1OW torr and back-filled with oxygen-free argon. After several such cycles the system was evacuated to 10e6 torr and the pressure adjusted by increasing the argon pressure using a micrometer valve. The use of oxygen-free argon as discharge gas enhanced the disintegration rate of the source material and prevented undesirable reactions between the sputtered deposit and the residual gas. Sot, 114 (6), June 1967,616619.
1855. Tantalum oxide films prepared by oxygen plasma and reactive sputtering. (USA)
30 anodization
The processes of glow discharge anodization and dc diode reactive sputtering were investigated for the formation of tantalum oxide films for thin-film capacitors. The dc reactive sputtering was carried out at a cathode potential of 4 kV and in an argon pressure of 30 mtorr. At this potential, it was found that the deposition rate of tantalum oxide (in &min) could be expressed as : 6x 1O-3 divided by the oxygen partial pressure in the oxygen-argon gas mixture (for the pressure range of oxygen from 8 x 1O-6 to 1 x 1O-2 torr, and an electrode spacing 10 cm). The gas phase anodization was carried out at a cathode potential of 1 kV and a pressure of 50 mtorr of oxygen. For this purpose a tantalum film deposited by sputtering in pure argon was used. Dielectrics up to a maximum thickness of 3000 8, could be prepared by these methods. The first method (dc reactive sputtering) produces thickness variations over 50 cmB of 4 to 20 per cent compared with the second method (glow discharge) which gave variations of 4 to 1 per cent. F Vratny, J Am Ceram Sot, 50 (6), June 1967,283-287. 30 1856. On using the method of cathode sputtering for the preparation of semiconducting compound thin films. (Czechoslovakia)
Equipment is described for preparing TnSb thin films by cathode sputtering. The dependence between the film thickness and electrical characteristics on sputtering parameters is stated. Since, in a glow discharge, no decomposition into free components will take place, the suitability for preparing other compound thin films by this method is discussed. J Cervenak,
Slabopr
Obzor,
28 (7), July 1967, 442-447
barriers
made
by localized
(in Czech).
30 sputtering
A device is described for the fabrication of fast diodes. Si-Au potential barriers are produced by the following method: on a Si plate a layer of SiO, is produced and a metal foil mask with a hole is attached. Then SiO, is removed under argon at 1O-3 torr by ionic etching, localized to the holes at the mask, Subsequently the apparatus is evacuated and Au film is evaporated through the same mask. In this way, Si-Au contacts with diameters as small as 100 microns have been made. Z Majewski, Bull Acad Polon Sci Sir Sci Tech, 15 (4), 1967, 343-346 (in English). 30 1858. Vacuum processes for the deposition of thin films.
(Germany) The similarities and characteristic differences of evaporation and condensation processes in high vacuum evaporation, cathodic sputtering, and plasma sputtering are explained. Applications of these techniques and the associated vacuum systems are described. Cathodic sputtering is considered as most suitable for the deposition of “high-boiling” materials, at rates of up to 10 &sec on small surfaces. High vacuum evaporation can be used for the de osition of most elements and compounds, at rates of 10e-lo3 1 /sec. The applications of these techniques include a very large field from microcircuits to plating of plastics and metals. KG Gunther, Chem Zng Tech, 39 (ll), June 1967,641~648 (in German).
Massa-
1854. Cd,Hg,,Te
H Kraus et al, J Electrochem
1857. Silicon-gold potential method. (Poland)
1859. Process for the vapour deposition (USA) radiation of the substrate.
of material
30 without thermal
The process consists of separating the vapour waves coming from the vapour source from the accompanying heat waves, by decomposing both types of waves simultaneously into impulses of definite length. The more rapid and therefore preceding heat wave impulses are caught by a moving screen system, while the relatively slower vapour wave impulses are allowed to pass through unhindered. A F Horn and A F Aldrian, US Patent 3,333,982, Patent Ofice, 841 (l), 1st Aug 1967, 230.
Official Gaz US
30 (USA) 1860. Reduction of oxides by ion bombardment. The deposition of a metal coating on a surface of an oxide body, such as barium titanate, copper oxide, iron oxide, silicon oxide, tantalum oxide and titanium oxide, comprises mounting the oxide body and a piece of metal within the chamber. Argon, helium, krypton, mercury, neon or xenon can be fed into the chamber for ionisation. A radio frequency signal is applied to the oxide body for bombarding and selectively removing oxygen from the surface. The bombarded surface is then coated with particles from the metal. Litton O&e,
Systems Inc, US Patent 3,336,211, 841 (3), 15th Aug 1967, 921.
Oficial
Gaz
US Patent
30
1861. Metal-film production. (Great Britain) Suitable for producing a thin metallic film on a substrate by vacuum deposition, a number of substrates are caused to be tumbled together while being subjected to the metal vapour under the required conditions of heat and vacuum, the proximity of the source of metal vapour to the overall volumetric space occupied by the substrates while they are being tumbled being variable to permit control of this process. In a preferred procedure, the specified volumetric space is shielded from the metal-vapour source, and the vapour is only permitted to reach the space via a special access area of variable predeterminable dimensions. American Components Inc, Brit Patent 1,074,901, Patent Abstr, 7 (30) part 5, 28th July 1967. 30
(Great Britain) Capacitors having stable capacitance, low dissipation factors and stable temperature coefficient for use in microminiaturized circuits are made by building up alternate layers of metal and vapourdeposited void-free poly-p-xylylene film. Films of at least 100 8, may be deposited on gold, silver, copper, aluminium, lead or selenium foil or wire with a bulk resistivity less than 100 and preferably less than 10 pohm cm. The resulting capacitors are self-healing in that any electrical breakdown or arcing may be removed by burning through 1862. Thin film capacitors.
623