Showing papers on "Contact resistance published in 1972"
IBM1
TL;DR: In this article, the TLM method is compared with other methods of determining contact resistivity, revealing the common source of error of the methods, and making comparisons between the two methods.
Abstract: This paper mainly offers guidance to the technologist who has to characterize metal‐semiconductor contacts for process development and production control. To abolish confusion clear definitions are proposed for the terms contact resistance and contact resistivity. Based on these definitions, methods of determining contact resistivity are discussed, revealing the common source of error of the methods and making comparisons. New methods like the TLM method are described and included in the comparison. Results of contact resistivity measurements on Al‐Si contacts over a wide range of silicon surface doping are presented.
474 citations
TL;DR: The relationship between the value of Rc and the contact structure is discussed in this article, and it is pointed out that Rc may be negative when its usual, phenomenological definition is used.
Abstract: Values of specific contact resistance Rc have been obtained for Sn, Sn:Ag, and Au:Ge:Ni contacts to N-type gallium arsenide of resistivity 0.4 to 30 Ωcm. An approximate relationship R e ∝ 1 N , where N is the bulk carrier concentration, was shown to apply. The relationship between the value of Rc and the contact structure is discussed. It is pointed out, in particular, that Rc may be negative when its usual, phenomenological definition is used.
53 citations
Patent•
28 Apr 1972TL;DR: In this article, high pressure electrical contacts are provided with a deformable ductile white metal, for example, white metals selected from the group consisting of Sn, Pb, Cd, Zn, Bi, In, alloys of at least two of these metals with each other and alloys with Sb, whereby the two coatings mutually deform one into the other to provide a gas tight contact at the region of deformation.
Abstract: High pressure electrical contacts are provided coated with a deformable ductile white metal, for example, white metals selected from the group consisting of Sn, Pb, Cd, Zn, Bi, In, alloys of at least two of these metals with each other and alloys of at least one of these metals with Sb. The coating metal advantageously provides an easily separable and reusable low contact resistance junction at low loads when the coated male member of the contact is in electrical contact with an electrically conductive element siliarly coated, whereby the two coatings mutually deform one into the other to provide a gas tight contact at the region of coating deformation.
25 citations
01 Apr 1972
TL;DR: In this article, the thermal contact resistance of a bolted joint is composed of two components: large scale constriction which is influenced by the extent of the interfacial pressure distribution and small scale constrictions which is dependent on the magnitude of the local pressure.
Abstract: The thermal contact resistance of a bolted joint is composed of two components: large scale constriction which is influenced by the extent of the interfacial pressure distribution and small scale constriction which is influenced by the magnitude of the local pressure. It is analytically shown how the roughness asperities at the contact surfaces of the joint affect these two constrictions but in opposite senses. The sum of the two effects, the total resistance, may increase or decrease with changing resistance and examples are given where an optimum roughness will minimize total joint resistance.
15 citations
10 citations
TL;DR: In this paper, the authors measured the resistance of the contact used in spreading resistance measurements on silicon and found that thermal emission over this barrier and tunnelling through the barrier influence significantly the contact resistance.
Abstract: The resistance of the contact used in spreading resistance measurements on silicon has been measured as a function of temperature. The results can be described by assuming a potential barrier in series with the true spreading resistance and it is shown that thermal emission over this barrier and (at low resistivities) tunnelling through the barrier influence significantly the contact resistance. The observed relationship between contact resistance and resistivity is explained by this model when the pressure effect on the silicon energy gap is taken into account.
7 citations
TL;DR: The great stability of gold alloys makes them an ideal basis for the development of precision resistance wires, both for standard resistors in high-accuracy measuring instruments and for potentiometers where a high resistivity is required combined with a low temperature coefficient, low contact resistance and good wearing characteristics.
Abstract: The great stability of gold alloys makes them an ideal basis for the development of precision resistance wires, both for standard resistors in high-accuracy measuring instruments and for potentiometers where a high resistivity is required combined with a low temperature coefficient, low contact resistance and good wearing characteristics
6 citations
TL;DR: In this article, it was shown that the dominant mechanism limiting the risetime of pulsed Gunn-effect oscillators is a parasitic resistance within the device, which can be reduced by careful control of the contact metallisation, or alternatively by the use of n+ contacts.
Abstract: It is shown that the dominant mechanism limiting the risetime of pulsed Gunn-effect oscillators is a parasitic resistance within the device. If this resistance is reduced by careful control of the contact metallisation, or alternatively by the use of n+ contacts, risetimes of 1 ns or less can be obtained. The cavity parameters are shown to have a 2nd-order effect only.
4 citations
TL;DR: In this article, the results of an experimental investigation of ion transport between aqueous solutions separated by thin single-crystal silver bromide membranes are reported, and two distinct types of experiments were performed: membrane-resistance experiments, which consisted of measuring the transmembrane electrical resistance under various test conditions using small amounts of transported charge; and membrane-transport experiments, where studied the effects of transporting large amounts of charge through membranes under different test conditions.
3 citations
TL;DR: In this paper, a comparison of the contact resistance versus load data for ultra pure iron, an iron-cobalt alloy and a cobalt molybdenum-chromium was used to illustrate the effect of substrate mechanical properties on static adhesion and the ability to convert these data for the estimation of the dynamic coefficient of friction under particular experimental conditions.
Abstract: Contact resistance has been used to characterize the processes of physical contact in metallic systems with ultra clean surfaces. The contact resistance versus load curves of iron and two cobalt alloys were used to demonstrate the existence of surface work hardening and interfacial creep during contact as well as the fracture characteristics of an interfacial junction as the load is removed. The presence of an adsorbed film of hydrogen or hydrogen ions on iron completely changes the contact process. A comparison of the contact resistance versus load data for ultra pure iron, an iron-cobalt alloy and a cobalt molybdenum-chromium was used to illustrate the effect of substrate mechanical properties on static adhesion and the ability to convert these data for the estimation of the dynamic coefficient of friction under the particular experimental conditions.
3 citations
Proceedings Article•
01 May 1972TL;DR: In this paper, an adherent and humidity resistant silver-only front contact was applied to n on p silicon solar cells, where the critical processing step was the removal of the diffused oxide layer.
Abstract: Methods have been found to apply an adherent and humidity resistant silver-only front contact to n on p silicon solar cells. The critical processing step was the removal of the diffused oxide layer. Humidity resistance is superior to present day commercial titanium-silver contacts and the electrical characteristics of the cells are excellent. Titanium, which is degraded by humidity and which is a source of heavy metal poisoning, has been eliminated from the contact.
TL;DR: In this article, a torsion balance technique was used to measure the relationship between the normal compressive load applied across crossed rod samples and the resultant contact resistance to ascertain the extent of contact area growth under anticipated service conditions.
Abstract: An apparatus is described for the real‐time analysis of sliding friction and normal force adhesion phenomena using ultrahigh vacuum techniques. Developed for the purpose of investigating the effects of surface cleaning, temperature, and deliberate gaseous contamination on the adhesion behavior of selected candidate materials for use in the NERVA nuclear rocket engine program, the system was designed to measure contact resistance by a four terminal ac (constant current‐voltage drop) instrument calibrated in resistance. Using a torsion balance technique the relationship between the normal compressive load applied across crossed rod samples and the resultant contact resistance is used to ascertain the extent of contact area growth under anticipated service conditions. The apparatus can accommodate sample temperatures to 3000 K and maintain gaseous environments from pressures of 1 atm to 10−11 Torr. Contact resistance in the range 103–10−4 Ω, normal compressive loads from 1 mg to 600 g, and/or tangential load...
TL;DR: In this paper, the authors measured the time response of several carbon resistance thermometers in the liquid helium temperature range and compared their results to the theoretical analysis of Komatsu and found that they were in fair agreement.
01 Jun 1972
TL;DR: In this paper, a theoretical analysis of the principles of interfacial thermal conductance between two heated metal surfaces in mutual contact was presented, and it was determined that when heat flows from one metal to the other, the flow lines converge toward the actual contact points since the thermal conductivities of the metals are much greater than any intervening medium such as air or fluids.
Abstract: A theoretical analysis of the principles of interfacial thermal conductance between two heated metal surfaces in mutual contact is presented. It was determined that when heat flows from one metal to the other, the flow lines converge toward the actual contact points since the thermal conductivities of the metals are much greater than any intervening medium such as air or fluids. The converging lines cause contact resistance, which is usually high compared to the resistances offered to heat flow by metals. The resultant variation in resistance can produce unreliable equipment for aerospace and industrial applications unless the conductance can be determined accurately.
TL;DR: In this article, high temperature thermomechanical surface treatment improved the wear resistance of case-hardened 18KhGT steel by 40-60% compared with ordinary heat treatment.
Abstract: 1.
The high temperature thermomechanical surface treatment improved the wear resistance of case-hardened 18KhGT steel by 40–60% compared with ordinary heat treatment.
2.
Increase of wear resistance of steel after TMST is caused by changes in the fine structure of steel which improve the contact resistance of microvolumes to plastic strain.
TL;DR: In this article, the frequency spectrum of the noise power density resulting from sliding motion is assumed to be influenced by the properties of the metal surface, and the causes of noise generation due to fluctuations in contact resistance are considered to be fairly well understood.
TL;DR: In this paper, the electrical current through silver contacts evaporated onto n-type gallium arsenide as a function of surface treatment was reported, and the expected high resistance was explained semiquantitatively in terms of a balance between cleaning and surface damage.
Abstract: The electrical current through silver contacts evaporated onto n-type gallium arsenide as a function of surface treatment is reported. Contacts to untreated gallium arsenide exhibit the expected high resistance. Surface cleaning by argon ion bombardment reduces the resistance by three orders of magnitude. The electrical resistance beyond 850 eV increases rapidly with ion bombardment energy. The resistance minimum at 850 eV is explained semiquantitatively in terms of a balance between cleaning and surface damage. This type of contact is appropriate for addition to a finished material whose properties are to be investigated, but may not be adequately ohmic for use on production devices.
TL;DR: In this paper, it was shown that hole mobility in p GaAs is self-consistent and is not influenced significantly by impurity scattering, contact resistance, or light-hole magnetoresistance.
Abstract: It is shown that our experimental data on hole mobility in p GaAs are self‐consistent and are not influenced significantly by impurity scattering, contact resistance, or light‐hole magnetoresistance.
01 Jan 1972
TL;DR: The resistor design program RESIST includes correction terms due to right-angle bends, geometrical correction in the end regions due to surface crowding, and correction due to cross-sectional current crowding and the contact resistance in the contact regions.
Abstract: The resistor design program RESIST includes correction terms due to right-angle bends, geometrical correction in the end regions due to surface crowding, and correction due to cross-sectional current crowding and the contact resistance in the contact regions. Chawla's recently published geometrical correction term is used to facilitate "one-shot" calculation of resistor length.
01 Jan 1972
TL;DR: In this paper, the authors report the results of an experimental and analytical investigation to determine the thermal contact resistance of several metal specimen pairs using a relatively new pulse technique, including aluminum 2024-T3, aluminum 6061-T6, aluminum 7075-T 6, copper 110, stainless steel 304, molybdenum, and Armco iron.
Abstract: This dissertation reports the results of an experimental and analytical investigation to determine the thermal contact resistance of several metal specimen pairs using a relatively new pulse technique. Metal specimens were aluminum 2024-T3, aluminum 6061-T6, aluminum 7075-T6, copper 110, stainless steel 304, molybdenum, and Armco iron. Thermal contact resistance was also determined for dissimilar metal specimen pairs of aluminum 6061-T6 copper 110 and aluminum 7075-T6 copper 110. Aluminum 7075-T6, copper 110, and stainless steel 304 specimens were tested to determine the variance of contact resistance with time after loading. Specimens were circular cylindrical disks between .033 and .061 inches thick and .788 inches in diameter. Specimen contacting surfaces were nominally flat and polished to a surface rms roughness of approximately 2 micro-inches. Axial loads were applied from 20.7 to 124.2 psi in a 10 micron (10-5mm Hg) vacuum and -10°F environment. Results of the experiments showed that the thermal contact resistance decreased with increasing load, ii