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Vacuum deposited molybdenum films
78
ABSTRACTS ON MICROELECTRONICS AND RELIABILITY
that films prepared at low temperatures (175°C and 190°C) were in the highest oxidation state. The infra-red spectra of films reduced by heating in forming gas were the same as those prepared at 230°C. Infra-red spectra of an intermediate type were found for films prepared at temperatures between these two extremes. Capacitors have been prepared with approximately 1~ thick manganese oxide films between the anodic tantalum oxide and an aluminium counter-electrode. The capacitors were formed by anodization to 15-20 V of a tantalum film deposited by sputtering onto an oxidized silicon wafer. These samples showed more high temperature thermal stability than capacitors prepared without the manganese oxide films. The capacitance was frequency dependent. The effect is discussed in some detail. Tungsten carbide-tungsten resistive glazes. K. M. ~ , C. HUA~G and R. MURPHY,Proc. 1966 Electron. Components Conf., Washington D.C., p. 1. Research results are presented on resistive glazes composed of intermetallic and metal particles dispersed in a glass matrix. Methods of preparing resistive glazes based on a WC/W conductor phase are given. The variation of sheet resistance with variation in conductor concentration, milling time, firing temperature, kiln atmosphere, substrate composition and conductor particle size are discussed. The effect of moisture upon tantalum oxide thin film capacitors. J. ~ ,
W. H. OaR and D. FASSSLL,Proc. 1966 Electron. Components Conf., Washington D,C., p. 348. The moisture sensitivity of tantalum-oxide thin film capacitors was studied as a function of relative humidity, dielectric thickness and counter-electrode material, size and thickness. It was determined that the site of moisture adsorption was at the counter-electrode-oxide interface. Capacitors with non-adherent gold counter-electrodes exhibited approximately a 3 per cent change in capacitance when cycled between 0 per cent and 87 per cent R.H. (25°C). The use of adherent nichrome-gold counter-electrodes reduced the capacitance response to 0.5 per cent under the same cycle conditions. The use of an organic impregnant, a polyethyIene-polybutylene mixture, reduced the capacitance sensitivity to approximately 0'07 per cent. Epitaxlal depo~tioa oft~dm.imm Nlenide. A. BRUNNSCHWEILER,Nature, January, 29 (1966), p. 493. It has been found ponible to produce large area single-crystal films of cadmium selenide in a conventional evaporator by using mica as an orientating substrate. The experimental method of producing the films is described. The films can be built up to a total thickness of 750-3000A; thicker films than this tend to flake off the substrate. V a c u u m depmfltzd m o l y b d e n u m films. R. A. HOLMWOODand R. GLANQ,J. Electrochon. Soc., 112,
No. 8, August (1965), pp. 827-831. Vacuum evaporation of molybdenum with an electron bombardment source on oxidized silicon wafers produces films whose properties depend on the condensation temperature. At 600°C or above, the films have resistivities comparable to molybdenum wire, satisfactory adhesion, and tolerable stress. They are potentially useful as interconnexions for silicon devices and monolithic circuits. All films are polycrystalline with (110) fibre texture. Other crystalilte orientations appear above 500°C, while simultaneously the intrinsic film stress becomes decreasingly ten~'le and, at 625°C, compressive. Film stress and preferred orientation are considered to result from the mteractton of lattice defects during the entire growth process and not merely from lattice distortions at the film substrate interface. Nomographic design of v a c u u m gasket seals. A. ROTH, Vacuum, 16, No. 3, p. 113. The design method presented, is based on expressing the leak rate of any gasket seal as a product of three factors characterizing the influence of the gas, of the geometry and of the force respectively. The new concepts of sealing factor and index of tightening are used in order to express the relationship between the abovementioned factors; on the one hand the construction data of the seal, and on the other the changes produced during the tightening process. The paper presents the equations developed and also a complete set of alignment charts set up for the design of gasket seals and the prediction of their performances. Ultrahigh v a c u u m station for thln film and residual gas analysis studies, G. A. RozC,ONYI, W. J. POLITO and B. SCHWAmTZ,Vacuum, 16, No. 3, p. 121. A bakeable, sputter-ion pumped ultra-hi.ghvacuum system capable of in situ residual gas analyses before, during, and after the deposition ot tl~in
ABSTRACTS ON MICROELECTRONICS AND RELIABILITY
that films prepared at low temperatures (175°C and 190°C) were in the highest oxidation state. The infra-red spectra of films reduced by heating in forming gas were the same as those prepared at 230°C. Infra-red spectra of an intermediate type were found for films prepared at temperatures between these two extremes. Capacitors have been prepared with approximately 1~ thick manganese oxide films between the anodic tantalum oxide and an aluminium counter-electrode. The capacitors were formed by anodization to 15-20 V of a tantalum film deposited by sputtering onto an oxidized silicon wafer. These samples showed more high temperature thermal stability than capacitors prepared without the manganese oxide films. The capacitance was frequency dependent. The effect is discussed in some detail. Tungsten carbide-tungsten resistive glazes. K. M. ~ , C. HUA~G and R. MURPHY,Proc. 1966 Electron. Components Conf., Washington D.C., p. 1. Research results are presented on resistive glazes composed of intermetallic and metal particles dispersed in a glass matrix. Methods of preparing resistive glazes based on a WC/W conductor phase are given. The variation of sheet resistance with variation in conductor concentration, milling time, firing temperature, kiln atmosphere, substrate composition and conductor particle size are discussed. The effect of moisture upon tantalum oxide thin film capacitors. J. ~ ,
W. H. OaR and D. FASSSLL,Proc. 1966 Electron. Components Conf., Washington D,C., p. 348. The moisture sensitivity of tantalum-oxide thin film capacitors was studied as a function of relative humidity, dielectric thickness and counter-electrode material, size and thickness. It was determined that the site of moisture adsorption was at the counter-electrode-oxide interface. Capacitors with non-adherent gold counter-electrodes exhibited approximately a 3 per cent change in capacitance when cycled between 0 per cent and 87 per cent R.H. (25°C). The use of adherent nichrome-gold counter-electrodes reduced the capacitance response to 0.5 per cent under the same cycle conditions. The use of an organic impregnant, a polyethyIene-polybutylene mixture, reduced the capacitance sensitivity to approximately 0'07 per cent. Epitaxlal depo~tioa oft~dm.imm Nlenide. A. BRUNNSCHWEILER,Nature, January, 29 (1966), p. 493. It has been found ponible to produce large area single-crystal films of cadmium selenide in a conventional evaporator by using mica as an orientating substrate. The experimental method of producing the films is described. The films can be built up to a total thickness of 750-3000A; thicker films than this tend to flake off the substrate. V a c u u m depmfltzd m o l y b d e n u m films. R. A. HOLMWOODand R. GLANQ,J. Electrochon. Soc., 112,
No. 8, August (1965), pp. 827-831. Vacuum evaporation of molybdenum with an electron bombardment source on oxidized silicon wafers produces films whose properties depend on the condensation temperature. At 600°C or above, the films have resistivities comparable to molybdenum wire, satisfactory adhesion, and tolerable stress. They are potentially useful as interconnexions for silicon devices and monolithic circuits. All films are polycrystalline with (110) fibre texture. Other crystalilte orientations appear above 500°C, while simultaneously the intrinsic film stress becomes decreasingly ten~'le and, at 625°C, compressive. Film stress and preferred orientation are considered to result from the mteractton of lattice defects during the entire growth process and not merely from lattice distortions at the film substrate interface. Nomographic design of v a c u u m gasket seals. A. ROTH, Vacuum, 16, No. 3, p. 113. The design method presented, is based on expressing the leak rate of any gasket seal as a product of three factors characterizing the influence of the gas, of the geometry and of the force respectively. The new concepts of sealing factor and index of tightening are used in order to express the relationship between the abovementioned factors; on the one hand the construction data of the seal, and on the other the changes produced during the tightening process. The paper presents the equations developed and also a complete set of alignment charts set up for the design of gasket seals and the prediction of their performances. Ultrahigh v a c u u m station for thln film and residual gas analysis studies, G. A. RozC,ONYI, W. J. POLITO and B. SCHWAmTZ,Vacuum, 16, No. 3, p. 121. A bakeable, sputter-ion pumped ultra-hi.ghvacuum system capable of in situ residual gas analyses before, during, and after the deposition ot tl~in