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Showing papers on "Contact resistance published in 1973"


Journal ArticleDOI
TL;DR: In this paper, the specific contact resistance ρc of Al and Pd2Si contacts has been measured on p- and n-Si substrates of uniform resistivity.
Abstract: The specific contact resistance ρc of Al and Pd2Si contacts has been measured on p- and n-Si substrates of uniform resistivity. The variation of ρc with substrate resistivity is described by the following equations: The specific contact resistance of Al contacts was found to be lower than the values of Pd2Si contacts on p-Si. Pd2Si contacts on both n- and p-Si, (111) orientation, become non-ohmic in the resistivity range 0.020−0.10 Ω- cm . The data in this study are not sufficient to distinguish a variation in ρc with substrate orientation. Specific contact resistance values of Pd2Si contacts on 0.005 Ω- cm (100) n- Si and 0.010 Ω- cm (100) p- Si were not significantly different from values expected for the (111) substrates.

34 citations


Journal ArticleDOI
TL;DR: In this article, the mechanics of closure for gold electric contacts cleaned by sputtering and closed with precise control of mechanical and environmental variables are described. But they do not report the results of their experiments.
Abstract: We describe equipment and report results of a study of the mechanics of closure for gold electric contacts cleaned by sputtering and closed with precise control of mechanical and environmental variables. The ultrahigh‐vacuum system, in which measurements are performed, is isolated from building vibrations. Our measurements include contact resistance, load, cold welding, creep, anelastic strain recovery, stress strain, yield stress, and strain hardening. We calculated an activation energy of 1200 ± 100 cal/mole for low‐temperature creep in gold.

33 citations


Journal ArticleDOI
TL;DR: In this article, an analog-computer study is made of one-dimensional heat conduction through two bars whose axes are in line and whose adjacent ends make and break contact periodically.
Abstract: An analog-computer study is made of one-dimensional heat conduction through two bars whose axes are in line and whose adjacent ends make and break contact periodically. The work extends a previous study to take account of imperfect thermal contact at the contact interface. The effect of frequency and duration of contact are also discussed.

21 citations


Journal ArticleDOI
TL;DR: In this paper, various etches for high resistive InP were investigated and the etching rates established and the contact resistance was found to depend strongly on the temperature cycle, specifically becoming smaller with decreasing alloying time.
Abstract: Various etches for InP are investigated and the etching rates established. For contacting of high resistive InP different metals are examined. Low resistive contacts may be reached by In, Sn, Au, Ni and Ge-containing alloys. The contact resistance is found to depend strongly on the temperature cycle, specifically becoming smaller with decreasing alloying time.

20 citations


Proceedings ArticleDOI
01 Jan 1973

16 citations


Journal ArticleDOI
TL;DR: A plating for electrical contact surfaces should be selected on the bases of acceptable electrical characteristics (in conjunction with common contact surfaces) and of adequate corrosion resistance in the anticipated environments as discussed by the authors. But the problem electrical interfaces which must be considered is between the selected plating and nonplated aluminum contact surfaces.
Abstract: A plating for electrical contact surfaces should be selected on the bases of acceptable electrical characteristics (in conjunction with common contact surfaces) and of adequate corrosion resistance in the anticipated environments. One of the problem electrical interfaces which must be considered is between the selected plating and nonplated aluminum contact surfaces.

13 citations


Patent
Michael G. Coleman1
07 May 1973
TL;DR: In this article, the aluminum-zinc alloy has been used in P-type III-V compound semiconductor materials to decrease the contact resistance, increase uniformity of the contact, improve wire bonding ease and quality, decrease electromigration, and decrease the substrate temperature for contact formation.
Abstract: There is disclosed an aluminum-zinc alloy ohmic contact for semiconductor materials and methods for providing these ohmic contacts. This aluminum-zinc alloy contact has special application in P-type III-V compound semiconductor materials, and particular advantage in lightly doped P-type III-V compound semiconductors, to decrease the contact resistance, increase uniformity of the contact, improve wire bonding ease and quality, decrease electromigration, and decrease the substrate temperature for contact formation. In addition this alunimum-zinc alloy provides that formation of brittle gold-aluminum intermetallic compounds on the surface of the contact is retarded or eliminated when gold wire is used for wire bonding. The aluminum-zinc contact is also used to advantage on elemental semiconductor materials and with II-VI compound semiconductor materials for the purpose of decreasing electromigration. Most importantly, in the P-type III-V compound semiconductors, a contact made from the aluminum-zinc alloy self-dopes the region directly under the contact, forming a highly doped region below the contact. The highly doped region is formed by zinc atoms from the alloy. Formation of the highly doped region in this manner is thus accomplished without the necessity of separate dopings and/or photolithographic steps.

11 citations


Patent
Klaudy Peter1
22 May 1973
TL;DR: An electrical contact device for high currents and high current pickup speeds comprises a ring-shaped rotating metallic contact element, with the inner circumference of which a roller-shaped contact element that is made of solid material and rotates about an axis, is in electrical contact.
Abstract: An electrical contact device for high currents and high current pickup speeds comprises a ring-shaped rotating metallic contact element, with the inner circumference of which a roller-shaped contact element that is made of solid material and rotates about an axis, is in electrical contact. The speed on the circumference of the roller-shaped contact element fully or almost fully coincides with the speed on the inner circumference of the ringshaped contact element. The ring-shaped contact element consists of an highly electrically conductive contact liquid which is held in an open groove by centrifugal force. The contact resistance and the friction losses of the contact device are very small.

7 citations


01 Nov 1973
TL;DR: In this paper, the structural integrity and effective thermal conductivity of three metallic-ceramic composite coatings were investigated on the combustion side of water-cooled, 12.7-centimeter throat diameter, hydrogen-oxygen rocket thrust chambers operating at 2.07 to 4.14 meganewtons per square meter chamber pressure.
Abstract: An experimental investigation of the structural integrity and effective thermal conductivity of three metallic-ceramic composite coatings was conducted. These coatings were plasma sprayed onto the combustion side of water-cooled, 12.7-centimeter throat diameter, hydrogen-oxygen rocket thrust chambers operating at 2.07 to 4.14 meganewtons per square meter chamber pressure. The metallic-ceramic composites functioned for six to 17 cycles and for as long as 213 seconds of rocket operations and could have probably provided their insulating properties for many additional cycles. The effective thermal conductivity of all the coatings was in the range of 0.7472 to 4.483 w/(m)(K), which makes the coatings a very effective thermal barrier. Photomicrographic studies of cross-sectioned coolant tubes seem to indicate that the effective thermal conductivity of the coatings is controlled by contact resistance between the particles, as a result of the spraying process, and not the thermal conductivity of the bulk materials.

6 citations


Journal ArticleDOI
TL;DR: In this paper, the contact resistance of materials being spot-welded is measured, and a device is described which measures the contact resistances electronically, and so indicates when welding conditions are suitable.
Abstract: If the contact resistance of materials being spot-welded is too high, due to surface contamination, destruction of the specimen may result because of excessive heating by the welding pulse. A device is described which measures the contact resistance electronically, and so indicates when welding conditions are suitable.

5 citations


Journal ArticleDOI
TL;DR: In this article, the current and temperature dependence of Au-Ni contacts on n-type GaP has been investigated and the value of the activation energy was calculated as 0·033 eV.
Abstract: A study of the current and temperature dependence of Au-Ni contacts on n-type GaP has been performed. From the data obtained the value of the activation energy was calculated as 0·033 eV. In addition, the optimum technological conditions (550°C, 2 min) of contact formation were also estimated from the measurements of the specific contact resistance as a function of alloying temperature.

Journal ArticleDOI
TL;DR: In this paper, a low compliance force transducer was used with a small lead rider and a gold flat with various surface film conditions to record forces, displacement, and contact resistance, and the results were consistent with Greenwood's theory of contact resistance for a cluster of minute metallic contact spots within the load support area.
Abstract: Low contact resistance between metal surfaces is often observed in spite of interposed lubricant and/or oxide films. To study this effect an apparatus is used with which normal force and tangential microdisplacement are applied between a small lead rider and a gold flat with various surface film conditions. Simultaneous oscillograph records are made of forces, displacement, and contact resistance. A unique low compliance force transducer allows direct recording of the frictional behavior during microdisplacement. Under nonoxidized and nonlubricated conditions, and with either oxide or stearic acid lubricant film alone, friction is high and contact resistance is low. With oxide and lubricant together, friction is much lower and slide is smooth, but contact resistance remains low and Ohm's law is obeyed. The results are consistent with Greenwood's theory of contact resistance for a cluster of minute metallic contact spots within the load-supporting area. The contact resistance of such a cluster is indisting...

Journal ArticleDOI
TL;DR: In this paper, the development of a gold-palladium-vanadium alloy that combines all these properties is described. But the alloy is not suitable for precision potentiometers, as a high resistivity is required with a low temperature coefficient of resistance, a low thermoelectric force against copper, low contact resistance and good wearing characteristics.
Abstract: For precision potentiometers a high resistivity is required together with a low temperature coefficient of resistance, a low thermoelectric force against copper, low contact resistance and good wearing characteristics. This article describes the development of a gold-palladium-vanadium alloy that combines all these properties.

Patent
02 Aug 1973
TL;DR: In this article, a contact material consisting of Au alloyed pref. with 2% of Ni has satisfactory strength (>=90 kg/mm2) and abrasion resistance; the contact resistance is low and constant; there is no cold-welding or segregation tendency.
Abstract: Contact materials consisting of Au alloyed pref. with 2% of Ni have satisfactory strength (>=90 kg/mm2) and abrasion resistance; the contact resistance is low and constant; there is no cold-welding or segregation tendency.

Patent
21 May 1973
TL;DR: In this paper, new oxide semiconductor-metal contact resistance elements having remarkably stable volt-ampere characteristics are provided, which are based on utilization of the property of the contact surfaces between the oxide semiconductors and the metals.
Abstract: New oxide semiconductor-metal contact resistance elements having remarkably stable volt-ampere characteristics are provided. The contact resistance elements comprise oxide semiconductors which have negative resistance and also possess such thermister constant B*K and specific resistance RoK Omega at 273*K as satisfy the relation B X Ro < OR = 104K Omega .*K, and metals which are highly anticorrosive and have high electric conductivity, attached thereto, and are based on utilization of the property of the contact surfaces between the oxide semiconductors and the metals.

Journal ArticleDOI
TL;DR: In this paper, the authors explored the causes of high-ohmic contact resistance by analyzing several integrated circuit samples with an ion microprobe and indicated presence of oxide and dopant depletion at the interface.
Abstract: Causes of high-ohmic contact resistance were explored by analyzing several integrated circuit samples with an ion microprobe. Presence of oxide and dopant depletion at the interface were indicated. Mapping of oxygen vs depth through an oxide revealed that not only the elements present, but also the layered structure of the material could be observed. The possible production of artifacts due to electrostatic charges on the surfaces of a sample was noted.


Proceedings ArticleDOI
01 Jan 1973
TL;DR: In this paper, a detailed electrical and metallurgical study of the Ni/Au-Ge contact system on epitaxial GaAs was performed using a new thin-film analysis technique combining Auger electron spectroscopy with sputter etching.
Abstract: The results of a detailed electrical and metallurgical study are presented for an Ohmic contact which is used in GaAs device technology. The electrical behavior of alloyed Ni/Au-Ge films on epitaxial n-type GaAs found from conventional current-voltage and capacitance-voltage techniques is correlated to the composition-depth profiles found using a new thin-film analysis technique combining Auger electron spectrsocopy with sputter etching. Below the eutectic temperature of the Au-Ge mixture, the Ni is shown to diffuse rapidly through the Au-Ge film. Above the Au-Ge eutectic temperature, the specific contact resistance is shown to drop by a factor of greater than 109as the Ge and Au diffuse into the GaAs. The presence of the Ni at the Au-Ge/GaAs interface is shown to markedly alter the resulting contact surface uniformity. The lack of a reproducible and reliable Ohmic contact to moderately doped n-type GaAs has been a persistent problem in metal-semiconductor technology. One widely used technique is to alloy evaporated metal layers, such as Ni/Au-Ge, to clean GaAs in order to obtain a low resistance contact (1-3). We report here a detail electrical and metallurgical study of the Ni/Au-Ge contact system on epitaxial GaAs; unique to our study is the new metallurgical technique of thin-film profiling using Auger electron spectroscopy and sputter etching. This work is an extension of the preliminary metallurgical results reported earlier on bulk material only (4).

Journal ArticleDOI
TL;DR: In this paper, a model of an elementary heat channel is analyzed which simulates the zone of contact with an oxide film and an equation is derived which describes the increment of contact resistance due to the presence of an oxide layer.
Abstract: A model of an elementary heat channel is analyzed which simulates the zone of contact with an oxide film. An equation is derived which describes the increment of contact resistance due to the presence of an oxide film. The theoretical results agree closely with test data.