Showing papers on "Contact resistance published in 1977"

The interdigitated back contact solar cell: A silicon solar cell for use in concentrated sunlight

Abstract: The theoretical and experimental performance of an interdigitated back contact solar cell is described. This type of cell is shown to have significant advantages over a conventional solar cell design when used at high concentration levels, namely, reduced internal series resistance, nonsaturating open-circuit voltage, and an absence of shadowing by front surface contacting fingers. The results of a computer study are presented showing the effects of bulk lifetime, surface recombination velocity, device thickness, contact dimensions, and illumination intensity on the conversion efficiency and general device operation. Experimental results are presented for solar illumination intensities up to 28 W/cm2.

Liquid phase epitaxial growth of GaAs from AuGeNi melts

Abstract: Epitaxial GaAs layers are grown from Au Ge and Au Ge Ni melts in order to study Ni/Au Ge/GaAs alloyed contacts. The solubility of GaAs in Au Ge and Au Ge Ni alloys has been measured. The electrical behavior of Au, Ge and Ni in Ni/Au Ge/GaAs alloyed contacts is also discussed. Based on the results of liquid phase epitaxial growth experiments, we suggest the conditions for making ohmic contacts with low specific contact resistance on n -type GaAs by Au Ge Ni alloys. The specific contact resistance of Ni/Au Ge/GaAs alloyed contacts is also measured.

AL/Si and Al/Poly‐Si Contact Resistance in Integrated Circuits

Abstract: This paper presents results on the effects of sintering temperature, sintering time, and contact geometry on Al/Si and Al/poly‐Si contact resistance. At sintering temperatures >450°C the resistance of p‐type contacts is virtually constant and independent of time. The resistance of n‐type contacts, particularly to poly‐Si, increases with increasing sintering temperature for . This is attributed to the precipitation of a p‐type (Al‐doped) layer on n‐contacts during sintering. The interface resistance of both Al/Si and Al/poly‐Si contacts is independent of the length of the contact and inversely proportional to the width of the contact.

Composite wire and fence made therefrom useful for security purposes

Abstract: At least two conductive wire elements which are separated from each other by a thin insulating layer such that as soon as a pressure is exerted on the composite wire at least one of the electrical characteristics, contact resistance and/or capacitance between the elements, changes to a measurable extent. A fence constructed of such composite wire has a circuit connected with both conductive wire elments for detecting any deviation in the nominal value of contact resistance and/or capacitance between them and for controlling an alarm circuit responsive to such deviation.

Electric contact material

Abstract: PURPOSE:To provide an electric contact material having good resistance to deposition, less consumption and a small contact resistance by a method wherein Ca-Bi, Ca-Pb cpds. are added to Ag-Sn based alloy and oxidized internally. CONSTITUTION:Ag is melted in a graphite crucible to which about 6% of Sn is added and melted to form molten metal of Ag-Sn alloy. Separately, Ca-Bi or Ca-Pb based intermetallic cpd. is melted in Ar atmosphere, is solidified, and crushed to proper size. Into the molten metal, either intermetallic cpd. in amount of 0.1- 1.5wt% is added, together with 0.05-1.0wt% of Ni metal additionally. The formed alloy is oxidized internally under oxygen atmosphere to selectively oxidize Sn, Ca-Bi, Ca-Pb and Ni. The process provides an electric contact material having a good resistance to consumption and deposition and a small contact resistance, and as such the material can be effectively used for circuit breakers or solenoid switches.

Niobium point-contact Josephson-junction behavior at 604 GHz

Abstract: We have measured the ac Josephson effect in Nb point contacts at 604 GHz (496 μm). We find the coupling of the far‐infrared radiation to the point contact to depend in a simple manner on the resistance of the contact. The behavior of the high‐resistance point contacts (50⩽R⩽200 Ω) is very reproducible, allowing a quantitative comparison of the data to the frequency‐dependent Werthamer theory. We also account for the effects of noise and heating and compare these to Tinkham’s heating theory.

Computer analysis of resistance and non-uniform illumination effects on concentrator solar cells

Abstract: A computer program has been developed to perform a two-dimensional matrix analysis of the voltage distribution in the top layer of concentrator solar cells in order to evaluate the important effects of top layer sheet resistance, contact grid geometry, and non-uniform illumination. The uniformity of illumination influences the cell efficiency through modifying the resistance losses in the cells. It is shown that introduction of lower top layer resistance (∼ 5 ohms/square) reduces the sensitivity of cell performance to illumination uniformity, which suggests important economic benefits for concentrator systems: reduced power loss (higher conversion efficiency) in solar cells at higher concentrations, and relaxed tolerances on illumination uniformity (lower concentrator cost).

Electrical contact material of TiC, WC and silver

Abstract: An electrical contact suitable for use in high-current switching or circuit breaking, comprising a mixture of silver or copper with an alloy of tungsten carbide and titanium carbide. The contact material preferably uses from about 10% to about 90% silver by weight, the remainder being (WTi)C alloy, and preferably the alloy component comprises from about 35% to about 50% of WC, the remainder of the alloy being TiC. The contact is preferably made by a powder metallurgical process, and provides not only good impact resistance, weld resistance and erosion resistance but, even more importantly, provides low contact resistance, i.e. low electrical resistance when current flows through the closed contacts even after repeated cycling, as shown by the low temperature rise of the contact in use.

Effect of vacuum ambience on Al–Si contacts

Abstract: Aluminum–silicon contacts are extensively used in integrated circuits. Contact resistance of Al–Si contacts is sensitive to silicon surface preparation, vacuum ambience of aluminum film deposition, and contact sintering conditions. Controlled contamination experiments have been carried out using H2O, O2, and CO during the aluminum film deposition to evaluate the effect on the Al–Si contact resistance. A known gas was admitted to the vacuum chamber by a controlled leak valve and the partial pressure of the gas was monitored with a UTI 100 C quadrupole mass analyzer. The substrates consisted of n‐type (111) silicon slices completely processed through boron base and phosphorous emitter diffusions. Al–Si contacts were sintered in the 400°–550°C temperature range in N2 ambience. Al surfaces and Al–Si interfaces were Auger characterized. These results along with the contact resistance data (determined with an appropriate test structure) have been examined and it is concluded that gaseous contaminants such as H2...

Resistance welding equipment

Abstract: PURPOSE:To control heat generation at a weld zone to an optimum condition by storing the contact resistance between electrodes and correcting the pressing force through comparing the resistance with detected values of contact resistance in subsequent welding. CONSTITUTION:The output of a reference voltage generator 12 is applied to one side of a voltage comparator 13 in which the input of other side is a feedback signal that indicates voltage between welding electrodes 1, 2. The comparator 13 compares the voltage between electrodes with the reference voltage and outputs a control signal that indicates the difference between the reference voltage and feedback voltage, and applies to a current controller after amplifying the same. The voltage between electrodes is amplified, passed through an A/D converter, and stored in a storage device 26. In subsequent welding, it is compared with voltage between electrodes obtained by applying weak current before supplying welding current, and the difference between the two voltages is calculated with an arithmetic device 28. The result of this calculation is outputted to the gate 29 and driving pulse is supplied to a pulse motor 48 of the welding head at every output of the arithmetic device 28, and preset pressing force is corrected according to the change of contact resistance.

SOME BULK AND THIN FILM PROPERTIES OF ZrPt3 AND HfPt3

Abstract: Bulk and thin films of ZrPt3 and HfPt3 specimens were prepared and evaluated with respect to their physical and electrical properties. Both thin and bulk specimens showed excellent corrosion resistance and electrical conductivity. In order to evaluate both properties simultaneously a relay contact test in which one pole of a double pole single throw relay was coated with HfPt3 was conducted. Under a resistive load of 7 amps at 110 volts the uncoated pole failed after ∿ 105 cycles. After the same number of cycles the coated pole had not failed and had a contact resistance of approximately one quarter that of the failed contact.

High dielectric strength field effect semiconductor device

Abstract: PURPOSE:To raise dielectric strength by electrically connecting a base region with a source region of a double diffusing type insulating gate FET wherein the stabilization of drain current is contrived. CONSTITUTION:A base region 5 of double diffused structure is provided around a source region 4 wherein the base region is extended from a gate region 5a to a contat curface 5b with a source electrode 8. And the electrode 8 is connected with the source and base. The contact resistance with the source electrode is reduced by a high concentration layer 11. Furthermore, an increase in the amount of current is tried by widening the gate width. This structure permits the current to flow into the source region 4 through the base region 5 even if impact ionization occurs. But few current will flow into a low concentration and high resistance substrate 1. Therefore, a back gate voltage becomes small and the potential drops at the base and source regions are remarkably reduced. A forward voltage applied to a junction between the P-type base 5 and the N-type source 4 becomes small. A kink phenomenon occurring at low gate voltage will be eliminated and ON dielectric strength will be improved at high gate voltage.

The Effect of Surface Segregation of Mg on the Contact Resistance of Al-0.5-Percent Mg

Abstract: Silver and Ag-W (10 weight percent W) were operated in a 5.I-A (peak) 308-V (peak) full-wave rectified dc circuit. The experimental switching system was operated 1.5 times per minute; the opening and closing velocities were 4 x 10-2 and 3 x 10-4 cm/s, respectively; the fully open contact spacing was 200 µm; and the contacts were closed for 3 s. The opening and closing of the contacts were controlled by a heater-bimetal combination attached to the moving contact. The following contact pairs were used: Ag versus Ag, Ag-W versus Ag-W and Ag versus Ag-W. All combinations of contact material and contact polarity were used. The experimental results showed that there was always a net transfer of contact material from the cathode to the anode. The volume of material transferred was strongly dependent upon whether the anode was the moving (hotter) or the fixed (cooler) contact: the greater erosion occurring when the anode was the hotter contact. For Ag versus Ag contacts thc erosion pattern resulted inone pip on the anode and one crater on the cathode. For Ag-W versus AgW contacts the presence of the small percentage of W resulted in multiple pip and crater formations. The experiments with the Ag versus Ag-W showed that the cathode electrode material determined the erosion pattern observed, i.e., when the Ag-W was the cathode, multiple pip and crater'formations occurred, but when Ag was the cathode, only a single pip and crater structure was observed. The presence of the W either in the cathode or in the anode decreased the observed erosion. These experimental results are discussed in terms of how the presence of W affects the emission characteristics of the cathode region and also affects the movement of the arc roots.

Silver-nickel electrical contact point material

Abstract: PURPOSE: To provide a stabilized silver-nickel electrical contact point material with low contact resistance by dispersing many slender nickel particles in silver matrix. COPYRIGHT: (C)1978,JPO&Japio

System for measuring contact resistance

Abstract: PURPOSE:To measure the contact resistance at braching points of bus bar wiring in factories and buildings utilizing ultrasonic waves, and to enable the measurement of contact resistance duringthe connection operation of non-coated conductors.

Ohmic contacts to low-resistivity ZnS: Preparation, noise properties and nature of contact resistance

Abstract: The results of simultaneous investigations of noise characteristics and contact resistance of different contacts to low-resistivity ( ρ b = 1–10 ohm cm) ZnS single crystals including so-called ohmic contacts with a contact resistance ρ c = 0.1–0.5 ohm cm 2 are described and analyzed. A conclusion is drawn that the difficulties in obtaining ohmic contacts to low-resistivity ZnS are connected with the presence on the semiconductor contact surface of acceptor centers filled by electrons which are responsible for the increase of band bending at the semiconductor surface. In the case of ohmic contacts the contact barrier is lowered significantly owing to formation of the ionized donor centers in the contact region; electrons penetrate such barriers by tunneling.

Manufacturing process of semiconductor device

Abstract: PURPOSE:To obtain junctions which have low contact resistance by inserting a porous silicon dioxide layer between the emitter domain and impurity bearing silicon dioxide layer.

Surface resistance measuring device

Abstract: PURPOSE:To create a space between an electrode and another leectrode set up on the surface of an oppressed variable measuring substance, and a high precision measuring device, so that it may measure and separate the surface resistance from the contact resistance of the electrode and the oppressed measuring substance by the current value corresponding to at least two different spaces.

Contact-Resistance Data Processing Using an On-Line Digital Microprocessor

Abstract: Instrumentation which automatically measures and records dry-circuit contact resistance as lying within one of five adjustable resistance ranges has been previously devised and reported by Jedynak [ 1 ]. In this paper, we report on a major modification and improvement of the equipment involving the use of a cation and improvement of the equipment involving the use of an on-line digital microprocessor, to greatly improve the resistance measurement resolution and to convert the voluminous stream of data into more useful forms. The new system uses a special-function digital-to-analog converter controlled by the microprocessor to measure and record, for each operation of the contact, the dry-circuit contact resistance as lying within any one of 4096 contiguous 0.1-m12 resistance bins ranging from 0 to 0.41 \Omeg . The microprocessor also computes a running mean and standard deviation of the contact resistance based on the previous several hundred measurements. After every several thousand contact operations and concurrent measurements, the mean and standard deviation are printed out on a standard Teletype. During this normal printout time, the contact-resistance distribution of the last several hundred measurements is graphically displayed on the Teletype also. Numerical guard bands are placed on the mean and deviation computations so that if the contact resistance characteristic changes significantly between normal display points then the on-going results are automatically printed out on the Teletype on what amounts to an expanded time base: Thus the experimenter is assured that his data always accurately reflect the dry-circuit contact behavior even over millions of contact operations.

Manufacturing method of silicon semiiconductor device

Abstract: PURPOSE:By forming a polycrystalline silicon film on the basic plate in front of the drive-in, etc, in the impure area which has been formed by the termal diffusion method, etc, by preventing the growth of SiO2 film on the surface area during the heat treatment, one manufactures the silicon semi-conductor device which has small contact resistance with the electrode and the impurity region

Furnace for glass fiber

Abstract: PURPOSE:A furnace for glass fiber making reduced in the contact resistance by holding the heating element between the ends of the electrode rods and the pressing rods and by pressing the above rods with springs.

The Electrical Effects of Radiation Damage Near the Interface of Schottky Barrier Contacts

Abstract: The effects of radiation damage on the terminal characteristics of GaAs Schottky contacts is reported. The damage causes band-bending and carrier removal effects changing both the barrier height and the contact resistance, and increasing the minority carrier level in the barrier. Results of a defect characterisation study are summarised and compared to previously reported work. In addition the thermal stability of the damage is considered.

Static contact resistance of usual metal under high compressive stress and for high current densities

Abstract: Static contact resistance for all combinations of usual metals (cold‐drawn copper, brass, aluminum, duraluminum, mild steel, and stainless steel) are measured for stresses of up to 16 kg/mm2 and current densities of up to 7.5 kA/mm2. A decreasing resistance has been found for increasing compressive stress and increasing current intensity. Very low resistance values have been observed (0.02 mΩ mm2) with cold‐drawn copper and aluminum.

Paints for forming electrically conductive coats

Abstract: PURPOSE:Paints for forming electrically conductive coats with extremely low electrical resistance without contact resistance, capable of adhering to heating sheets in one piece, obtained by dispersing a specific metal and a specific resin in an aqueous medium.