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Electrical properties of thin films—dielectrics. Deposition methods of dielectric films and their electrical properties
World Abstracts on Microelectronics and Reliability
Crossover chips for hybridqntegrated film circuits. K. BREUNINGER, D. R. HABERLANDand R. HERBERGER.FeinwkTech. Messtechnik 85, (8) 369 (1977). (In German.) Most crossover methods are too complicated and expensive for use with small numbers of conductor crossovers in film circuits. Hybrid-type crossover chips have been developed for such purposes. They can be fitted in film circuits by cementing or reflow soldering without requiring extra time. Use may be made of the same methods as for diodes and transistors in SOT 23 cases or for ceramic chip capacitors.
363
cant rectification was found only, when evaporation techniques were used. For this type of diode the Nb-Nb2Os interface is generally assumed to act as ohmic contact, whereas the Nb2Os-Au interface behaves like a Schottky contact. Conduction mechanisms relevant to the various portions of the I-V characteristics are discussed. Current drifts are also treated, which are attributed to the migration of ionized traps. A theoretical model explaining the drift phenomena is presented.
Failure analysis techniques applied in resolving hybrid microThickness dependent effects of thermal ageing in thin con- circuit reliability problems. G. H. EBEL. 15th A. Proc. Reliab. ductive films. A. J. TOSSER, C. R. TELLIER and J. LAUNEY. Phys. IEEE Nevada. p. 70 (1977). The failure analysis highlighted in this paper concentrates on long term time depenVacuum 27, (4) 335 (1977). A1 and Zn films, l l0-900A thick, are dc or rf sputtered; SnO2 films in the 1500- dant problems not usually detected during standard screen8000 A thickness-range are rf sputtered. Thickness depen- ing tests. A detailed study of some of these problems can dence variations in electrical resistance are consistent with a lead to better processing and screening of hybrids. This two-layer model: the first layer, less than 150 A thick, is in turn, will result in better field reliability of hybrids. Failure analysis techniques can be used during the hybrid the thinner continuous layer that may be obtained; the second layer has a surface smoothness increasing with development phase to improve the device reliability before it thickness up to a value near 1300 ,~, above this thickness enters the production phase. Unfortunately, most hybrid the surface ordering progressively decreases. Mayadas- failure analyses are of the post-mortem variety. Applications Shatzkes conduction (with a constant grain diameter) occurs of both techniques will be discussed. Probably the most effective use of preventative failure within metal films; thus the electronic reflection factor on grain boundaries and the electronic specular reflection factor analyses is in the area of wire bonding. Most "pie chart" on interfaces are determined. Thermal ageing slightly modi- failure history presentations show wire bonding to be a major fies the grains but improves the interface specular factor hybrid failure mode. When high temperature (300°C range) and induces thickness dependent ageing effects. Variations wire bond failure evaluation is used to establish bonding in the tcr of metallic films are consistent with the two-layer schedules and controls, defective bonds no longer are a major contributor to hybrid failures. Two other preventative model and the approximate M-S equations. techniques that will be discussed are multilevel substrate evaluation and loose particle recovery and analysis. Electrical properties of thin films--dielectrics. Deposition One of the categories of hybrid failures that rates near methods of dielectric films and their electrical properties. the top of most historical studies is the moisture/conD. S. CAMPBELL. Vacuum 27, (4) 213 (1977). The various tamination related failures. Entrapped chlorine in chip methods of depositing thin (< 1/~m) dielectric films are summarized. This summary is followed by a brief survey of capacitor end terminations is one example of a moisture/ the basic electrical properties and also of the applications contamination problem. Other problems in this category of thin dielectric films with particular reference to deposition that will be discussed include active device failures caused by spittle, and substrate metalization shorts caused by gold techniques. It is concluded that it is not possible to give a "best buy" for a preparation method, as so much depends and silver migration. The dangers of using conductive epoxy for primary elecon the electrical studies to be made or the applications trical connections will be explored. This is a more subtle which are envisaged. type of time dependant failure mode that, in general, will not be detected as a result of normal screening tests. l / f noise voltage in a thin film structure. S. HUSA. Vacuum Improper eutectic die and substrate attachment can gener27, (4) 345 (1977). 1/f noise in current carrying thin film ate particles that have resulted in device failures. This devices is caused by fluctuation of the electrical conductivity problem along with some recommended corrective action of the film material. Describing its effect on the voltage will be presented. distribution in a device requires a two-dimensional analysis. In order to improve hybrid yields, when delidding is not This may be done by means of a theory, presented in this allowed, open package burn-in has been proposed. Some article, where the fluctuation is treated as current dipoles. of the hazards associated with such a burn-in will be highThe geometrical dependence of the noise intensity across lighted. Examples of wire bond and integrated circuit deelectrodes on Hall generator structures, made from InSb gradation resulting from open package burn-in will be thin films, is measured. This is in fair agreement with preincluded. dictions based on the theory. Conduction phenomena in Nb-Nb 20s-Au thin film structures fabricated by various techniques. E. Scml and g. CHAMIcovsKv. Vacuum 27, (4) 299 (1977). Conduction mechanisms have been studied in niobium-niobium oxide-gold thin film sandwich structures with the oxide prepared by anodic oxidation and reactive sputtering, respectively. Different I-V characteristics have been obtained with diodes having gold electrodes made by both evaporation and sputtering. Signifi-
9. E L E C T R O N ,
Hybrid interconnection of LC.'s by means of patterns on flexible tape. A. VAN DER DRIFT and K. NICKL VAN NIKELSBERG.Electrocomp. Sci. Technol. 4, 53 (1977). Mounting of I.C.'s on thickfilm circuits by means of patterns on foil of a total thickness of about 30 microns is described. The extreme flexibility of the foil and some well controlled characteristics of the thickfilm process aid soldering of the chip with a reproducible low heat resistance to the substrate in a cheap and reliable way.
ION AND LASER BEAMS
Electron beam scans 2-/tm patterns directly on Japanese wafer. Electronics p. 7E (24 November 1977). Japanese researchers have taken two major steps along the road to electron-beam fabrication of very-large-scale integrated
circuits. With direct electron-beam exposure of photoresist on wafers, they have fabricated a 1096-bit memory with a minimum line width of 2 micrometers. They also have used electron-beam exposure to produce a complete set of 2-#m
Crossover chips for hybridqntegrated film circuits. K. BREUNINGER, D. R. HABERLANDand R. HERBERGER.FeinwkTech. Messtechnik 85, (8) 369 (1977). (In German.) Most crossover methods are too complicated and expensive for use with small numbers of conductor crossovers in film circuits. Hybrid-type crossover chips have been developed for such purposes. They can be fitted in film circuits by cementing or reflow soldering without requiring extra time. Use may be made of the same methods as for diodes and transistors in SOT 23 cases or for ceramic chip capacitors.
363
cant rectification was found only, when evaporation techniques were used. For this type of diode the Nb-Nb2Os interface is generally assumed to act as ohmic contact, whereas the Nb2Os-Au interface behaves like a Schottky contact. Conduction mechanisms relevant to the various portions of the I-V characteristics are discussed. Current drifts are also treated, which are attributed to the migration of ionized traps. A theoretical model explaining the drift phenomena is presented.
Failure analysis techniques applied in resolving hybrid microThickness dependent effects of thermal ageing in thin con- circuit reliability problems. G. H. EBEL. 15th A. Proc. Reliab. ductive films. A. J. TOSSER, C. R. TELLIER and J. LAUNEY. Phys. IEEE Nevada. p. 70 (1977). The failure analysis highlighted in this paper concentrates on long term time depenVacuum 27, (4) 335 (1977). A1 and Zn films, l l0-900A thick, are dc or rf sputtered; SnO2 films in the 1500- dant problems not usually detected during standard screen8000 A thickness-range are rf sputtered. Thickness depen- ing tests. A detailed study of some of these problems can dence variations in electrical resistance are consistent with a lead to better processing and screening of hybrids. This two-layer model: the first layer, less than 150 A thick, is in turn, will result in better field reliability of hybrids. Failure analysis techniques can be used during the hybrid the thinner continuous layer that may be obtained; the second layer has a surface smoothness increasing with development phase to improve the device reliability before it thickness up to a value near 1300 ,~, above this thickness enters the production phase. Unfortunately, most hybrid the surface ordering progressively decreases. Mayadas- failure analyses are of the post-mortem variety. Applications Shatzkes conduction (with a constant grain diameter) occurs of both techniques will be discussed. Probably the most effective use of preventative failure within metal films; thus the electronic reflection factor on grain boundaries and the electronic specular reflection factor analyses is in the area of wire bonding. Most "pie chart" on interfaces are determined. Thermal ageing slightly modi- failure history presentations show wire bonding to be a major fies the grains but improves the interface specular factor hybrid failure mode. When high temperature (300°C range) and induces thickness dependent ageing effects. Variations wire bond failure evaluation is used to establish bonding in the tcr of metallic films are consistent with the two-layer schedules and controls, defective bonds no longer are a major contributor to hybrid failures. Two other preventative model and the approximate M-S equations. techniques that will be discussed are multilevel substrate evaluation and loose particle recovery and analysis. Electrical properties of thin films--dielectrics. Deposition One of the categories of hybrid failures that rates near methods of dielectric films and their electrical properties. the top of most historical studies is the moisture/conD. S. CAMPBELL. Vacuum 27, (4) 213 (1977). The various tamination related failures. Entrapped chlorine in chip methods of depositing thin (< 1/~m) dielectric films are summarized. This summary is followed by a brief survey of capacitor end terminations is one example of a moisture/ the basic electrical properties and also of the applications contamination problem. Other problems in this category of thin dielectric films with particular reference to deposition that will be discussed include active device failures caused by spittle, and substrate metalization shorts caused by gold techniques. It is concluded that it is not possible to give a "best buy" for a preparation method, as so much depends and silver migration. The dangers of using conductive epoxy for primary elecon the electrical studies to be made or the applications trical connections will be explored. This is a more subtle which are envisaged. type of time dependant failure mode that, in general, will not be detected as a result of normal screening tests. l / f noise voltage in a thin film structure. S. HUSA. Vacuum Improper eutectic die and substrate attachment can gener27, (4) 345 (1977). 1/f noise in current carrying thin film ate particles that have resulted in device failures. This devices is caused by fluctuation of the electrical conductivity problem along with some recommended corrective action of the film material. Describing its effect on the voltage will be presented. distribution in a device requires a two-dimensional analysis. In order to improve hybrid yields, when delidding is not This may be done by means of a theory, presented in this allowed, open package burn-in has been proposed. Some article, where the fluctuation is treated as current dipoles. of the hazards associated with such a burn-in will be highThe geometrical dependence of the noise intensity across lighted. Examples of wire bond and integrated circuit deelectrodes on Hall generator structures, made from InSb gradation resulting from open package burn-in will be thin films, is measured. This is in fair agreement with preincluded. dictions based on the theory. Conduction phenomena in Nb-Nb 20s-Au thin film structures fabricated by various techniques. E. Scml and g. CHAMIcovsKv. Vacuum 27, (4) 299 (1977). Conduction mechanisms have been studied in niobium-niobium oxide-gold thin film sandwich structures with the oxide prepared by anodic oxidation and reactive sputtering, respectively. Different I-V characteristics have been obtained with diodes having gold electrodes made by both evaporation and sputtering. Signifi-
9. E L E C T R O N ,
Hybrid interconnection of LC.'s by means of patterns on flexible tape. A. VAN DER DRIFT and K. NICKL VAN NIKELSBERG.Electrocomp. Sci. Technol. 4, 53 (1977). Mounting of I.C.'s on thickfilm circuits by means of patterns on foil of a total thickness of about 30 microns is described. The extreme flexibility of the foil and some well controlled characteristics of the thickfilm process aid soldering of the chip with a reproducible low heat resistance to the substrate in a cheap and reliable way.
ION AND LASER BEAMS
Electron beam scans 2-/tm patterns directly on Japanese wafer. Electronics p. 7E (24 November 1977). Japanese researchers have taken two major steps along the road to electron-beam fabrication of very-large-scale integrated
circuits. With direct electron-beam exposure of photoresist on wafers, they have fabricated a 1096-bit memory with a minimum line width of 2 micrometers. They also have used electron-beam exposure to produce a complete set of 2-#m