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Showing papers on "Contact resistance published in 1983"


Journal ArticleDOI
Tung-Sheng Kuan1, Philip E. Batson1, Thomas N. Jackson, Hans S. Rupprecht1, E. L. Wilkie1 
TL;DR: In this paper, the interface structures resulting from the alloying reactions between a Au/Ni/Au-Ge composite film and a (100) GaAs substrate were studied by transmission electron microscopy and scanning transmission electron microscope.
Abstract: The interface structures resulting from the alloying reactions between a Au/Ni/Au‐Ge composite film and a (100) GaAs substrate were studied by transmission electron microscopy and scanning transmission electron microscopy. Electron microscope examinations of the cross‐sectional samples prepared in this study offered excellent lateral and depth resolution of local structures which are not available by other analytical techniques used previously in similar studies. The distributions and chemical compositions of various phases formed, and the morphologies of the interfaces between these phases were monitored and compared with the measured contact resistances at three different stages of alloying. A correlation between the interface structure and the contact resistance was found.

225 citations


Journal ArticleDOI
TL;DR: In this paper, a four-terminal microelectronic test structure and test method are described for electrically determining the degree of uniformity of the interfacial layer in metal-semiconductor contacts and for directly measuring interfacial contact resistance.
Abstract: A four-terminal microelectronic test structure and test method are described for electrically determining the degree of uniformity of the interfacial layer in metal-semiconductor contacts and for directly measuring the interfacial contact resistance. A two-dimensional resistor network model is used to obtain the relationship between the specific contact resistance and the measured interfacial contact resistance for contacts with a uniform interfacial layer. A new six-terminal test structure is used for the direct measurement of end contact resistance and the subsequent determination of front contact resistance. A methodology is described for reducing the effects of both contact-window mask misalignment and parasitic resistance associated with these measurements. Measurement results are given for 98.5-percent Al/1.5- percent Si and 100-percent Al contacts on n-type silicon.

187 citations


Journal ArticleDOI
Simon S. Cohen1
TL;DR: In this article, the problem of low resistance ohmic contacts to silicon has been of considerable technological interest, and several methods for contact resistance determination have been introduced in the past, including two-, three-and four-terminal resistor methods of measurement.

89 citations


Journal ArticleDOI
TL;DR: The different techniques of making ohmic contacts to p-type CdTe are reviewed and discussed in this paper, where it is shown that the HgTe contacts deposited by close spacing isothermal growth present a room temperature specific contact resistance ten times lower than so far reported.
Abstract: The different techniques of making ohmic contacts to p-type CdTe are reviewed and discussed. Mercury telluride, whose work-function matches perfectly that of p-type CdTe, is shown to be more favourable than Au or Pt. The HgTe contacts deposited by close spacing isothermal growth present a room temperature specific contact resistance ten times lower than so far reported. Hall effect measurements have been performed down to low temperatures on several undoped p-type CdTe and Cd0.7Hg0.3Te crystals. Ionisation energies of 0.05-0.07 and 0.13 eV for CdTe and 0.024 eV for Cd0.7Hg0.3Te have been determined and the nature of the responsible centres discussed.

79 citations


Journal ArticleDOI
TL;DR: In this article, the effect of impurities in the carbon paste on the characteristics of solar cells is investigated, and the series resistance and the conversion efficiency are shown to exhibit a strong dependence on O2 concentration in the heating atmosphere.
Abstract: Heating conditions of carbon electrodes for CdTe and the effect of impurities in the carbon paste on the characteristics of solar cells are investigated. The series resistance (Rs) and the conversion efficiency (ηi) of solar cells exhibit strong dependence on O2 concentration in the heating atmosphere. Addition of Cu to the carbon paste causes Rs and diode factor (n) to decrease, resulting in a remarkable improvement in ηi. As a result of preparation of low resistance contact electrode for CdTe, a cell with 0.78 cm2 active area which was made from 50 ppm Cu-added carbon paste showed Voc=0.754 V, Isc=0.022 A, FF=0.606 and ηi=12.8%.

66 citations


Journal ArticleDOI
Norman Braslau1
TL;DR: In this article, the present capability of obtaining ohmic contacts to GaAs over a range of doping levels is reviewed and possible models of transport across the metal-semiconductor interface are discussed and contact techniques are described.

61 citations


Patent
14 Jan 1983
TL;DR: In this paper, a double hetero junction structure is formed on the semiconductor substrate and a current blocking layer is added to prevent the deformation of the electrode in order to enable a current constricting structure to be formed.
Abstract: PURPOSE:To enable a current constricting structure to be formed in self-alignment with an optical waveguide structure and to prevent the increase in contact resistance between a contact layer and an electrode and the deformation of the electrode, by providing a contact layer having a second type of conductivity on a clad layer having the second type of conductivity and a current blocking layer. CONSTITUTION:A semiconductor laser device according to the present invention comprises a semiconductor substrate 11 having a first type of conductivity, a clad layer 14 having the first type of conductivity, an active layer 15 and clad layers 16-18 having a second type of conductivity and having a linear projection 18 thereon. A double hetero junction structure is thus formed on the semiconductor substrate 11. The semiconductor laser device further comprises a current blocking layer 21 formed on this double hetero junction structure except at least a part of the projection 18 of the clad layers having the second type of conductivity, and contact layers 20 and 22 having the second type of conductivity and formed on the second-conductivity-type clad layers 16-18 and the current blocking layer 21. For example, the semiconductor substrate 11 and the contact layers 20 and 22 may be formed of GaAs and the double hetero junction structure 14-18 may be formed of InGaAlP. Further, an InGaP buffer layer 13 of the first type of conductivity is provided between the GaAs substrate 11 and the InGaAlP clad layer 14 having the first type of conductivity.

49 citations


Journal ArticleDOI
TL;DR: In this article, the spreading resistance due to current crowding at the end points of an FET channel is investigated and an analytic expression is derived giving this resistance as function of a few parameters.
Abstract: The spreading resistance due to current crowding at the end-points of an FET channel is investigated. An analytic expression is derived giving this resistance as function of a few parameters. Two-dimensional numerical simulations, using finite-element techniques, confirm the accuracy of the simple analytical approach. For short channel devices the current crowding effect is found to give a nonnegligible contribution to the total source resistance. In order to optimize the FET performance, the geometry and conductivity of the source/drain regions must be carefully designed, trading off short channel effect and transconductance degradation.

44 citations


Journal ArticleDOI
TL;DR: In this paper, the characteristics of Au:Ge, Ni/Au:Ge and Au/Ni/Ge metallizations were compared to ion-implanted and epitaxial n -GaAs layers on semi-insulting substrates.
Abstract: We have investigated and compared the characteristics of Au:Ge, Ni/Au:Ge and Au/Ni/Au:Ge ohmic contact metallizations to ion-implanted and epitaxial n -GaAs layers on semi-insulting substrates. Auger depth profiles of ohmic contacts and SEM of surface microstructures have provided significant insight as to the nature and degradation mechanism of ohmic contacts with aging. An electrolytic tank model with distributed resistors representing nodular or cluster form contacts has been successfully used to understand the effects of non-uniform ohmic contacts. A small degree of change in the semiconductor sheet resistance in the gaps between contacts, with aging at an elevated temperature, has been attributed to possible lateral surface diffusion of Au in the Au:Ge contacts and Ge in the Ni/Au:Ge and Au/Ni/Au:Ge contacts.

42 citations


Journal ArticleDOI
TL;DR: A simple metallurgical model is proposed which is based on the AuGe being the main reactive system at the interface responsible for the formation of the rectangular particles which are the pathways for the current as mentioned in this paper.
Abstract: Auger depth profiling, electron probe microanalysis, electron beam induced current and conventional scanning electron microscopy have been used to study the inhomogeneous reaction which takes place during the alloying of evaporated AuGe films on (100), n-type GaAs. These measurements have been correlated with I–V and C–V data taken for heat treatment below the AuGe eutectic temperature (360°C) and specific contact resistance measurements above 360°C. The picture which emerges is that of the key role of the germanium in the metallurgical reaction, in addition to its accepted role as the n+ dopant. A simple metallurgical model is proposed which is based on the AuGe being the main reactive system at the interface responsible for the formation of the rectangular particles which are the pathways for the current. Minimum contact resistance correlates with the maximum growth of these particles.

38 citations


Journal ArticleDOI
TL;DR: In this paper, a procedure theorique d'optimisation de l'epaisseur d'un materiau d'insertion for minimising the resistance thermique de contact entre des surfaces planes rugueuses is presented.
Abstract: Presentation et verification experimentale d'une procedure theorique d'optimisation de l'epaisseur d'un materiau d'insertion pour minimiser la resistance thermique de contact entre des surfaces planes rugueuses

Journal ArticleDOI
TL;DR: In this article, the redistribution of As during Pd2Si formation with electrical measurements was investigated and it was shown that the As redistribution can be used to adjust the barrier height of Schottky diodes and other applications in submicron integrated circuit technology.
Abstract: We have investigated the redistribution of As during Pd2Si formation with electrical measurements. Our results are in agreement with the earlier findings that part of the shallow implanted As is pushed ahead by the moving silicide‐silicon interface at 250 °C. We show that, owing to the As redistribution, Pd2Si contacts can be formed to shallow junction diodes without altering the junction properties, because the junction is displaced by the approaching silicide‐silicon interface. We also demonstrate that the increase in the As concentration beneath the silicide‐silicon interface reduces contact resistance. Finally, we discuss the use of the As redistribution to adjust the barrier height of Schottky diodes and other applications in submicron integrated circuit technology.

Journal ArticleDOI
TL;DR: In this paper, the authors measured prealloy and postalloy contact resistances at [(Al−Si)/bulk (100)Si] interfaces for a range of Al-Si alloy compositions (0-2 at.% Si), alloying temperatures (325-550 C), and contact sizes (3-5 μm).
Abstract: Prealloy and postalloy contact resistances at [(Al–Si)/bulk (100)Si] interfaces have been measured for a range of Al–Si alloy compositions (0–2 at.% Si), alloying temperatures (325–550 °C), and contact sizes (3–5 μm). Contact doping for n+/p junctions was by diffusion from a POCl3 source; for p+/n junctions, by diffusion from a BN source. Al–Si deposition was by S–Gun■ magnetron sputtering. Statistical distributions of prealloy contact resistance to n+ Si were found to provide highly sensitive monitors of contact cut and deposition‐system cleanliness.. Minimum postalloy contact resistance values were independent of Al–Si alloy composition, and silicon pitting in the contact cut was not required to achieve good Ohmic contact. The maintenance of consistent, low‐resistance Ohmic contacts throughout postalloy processing was found to depend on the silicon concentration in the aluminum being high enough to keep the aluminum supersaturated during all postdeposition temperature cycling.

Journal ArticleDOI
TL;DR: In this paper, contact resistance measurements were made for the electrodes formed on highly doped shallow p-Si layers, where lamp sintering was performed at 450°C and a specific contact resistance of 4.0×10-6 Ohm-cm2 was achieved for p+ layers.
Abstract: Reduction of contact resistance was achieved in Al/Si ohmic electrodes sintered by halogen lamp rapid heating. Contact resistance measurements were made for the electrodes formed on highly doped shallow p-Si layers, where lamp sintering was performed at 450°C. The contact resistance was low and uniform within a wafer when compared with that for conventional furnace sintering. A specific contact resistance of 4.0×10-6 Ohm-cm2 was achieved for p+ layers. The Al spikes and Si precipitates could be markedly reduced in this short time sintering.

Journal ArticleDOI
Thomas P. Pearsall1, R.H. Hendel2, P. O'Connor2, K. Alavi, A.Y. Cho2 
TL;DR: In this article, selectively-doped depletion-mode FETs with transconductance in excess of 90 mS/mm and contact resistance less than 0.4 Ω-mm have been fabricated.
Abstract: Selectively-doped depletion-mode FET's which show full pinch-off at 295 K with transconductance in excess of 90 mS/mm and contact resistance less than 0.4 Ω-mm have been fabricated. The device properties reported represent a significant improvement over previously published work on an equivalent structure, because of improvements in growth technique and modifications in the device structure. Analysis of our measurement at room temperature suggests that the two-dimensional electron gas at the hetero-interface is not the dominant contributor to the total device current.

Journal ArticleDOI
S. Sharma1, L. Hines1
TL;DR: In this paper, it has been found that for temperatures up to 200°C, Ru oxidizes to produce a film which causes high contact resistance, whereas for temperatures >300°C Ru forms an oxide film, RuO 2, which has low contact resistance.
Abstract: Ruthenium (Ru) has been heated in air in the range of 100-400°C in order to investigate its usefulness for electrical contacts. It has been found that for temperatures up to 200°C, Ru oxidizes to produce a film which causes high contact resistance. For temperatures >300°C, Ru forms an oxide film, RuO 2 , which has low contact resistance. Electron spectroscopy for chemical analysis (ESCA) reveals that the oxide which forms at temperatures 300°C). More work is required to define precisely the temperature above which RuO 2 is the predominant species. Ru contacts in actual applications will be subjected to temperatures <100°C. This may make Ru an inappropriate contact material.

Journal ArticleDOI
TL;DR: In this article, it was shown that the contact resistivity of thin TiN layers changes in opposite ways for p + and n + Si after vacuum annealing at 600°C for 15 min, consistent with an increase of the barrier height φ Bn of the contact by ≅ 0.1 V to near midgap value.
Abstract: The standard transmission line model cannot be applied to evaluate the contact resistivity of thin TiN layers on highly doped p + and n + substrates because the finite sheet resistance of the TiN must be accounted for. We present two ways to include this effect using existing analytical models. The results are shown to agree with measurements where the effect of the finite sheet resistance of TiN is eliminated with a metallic overlayer. With the help of these evaluation techniques, it is shown that the contact resistivity of TiN changes in opposite ways for p + and n + Si after vacuum annealing at 600°C for 15 min. This result is consistent with an increase of the barrier height φ Bn of the contact by ≅0.1 V to near midgap value.

Journal ArticleDOI
TL;DR: In this article, e-beam sintering of refractory metal contacts on implanted n+- and p+-silicon layers was used to achieve contact resistivities as low as 1.5 × 10-7Ω.
Abstract: Low contact resistance for metal on silicon is particularly important for VLSI where contact dimensions become ≤1 µm. This paper reports on e-beam sintering of refractory metal contacts on implanted n+- and p+-silicon layers. With this technique, we have obtained contact resistivities as low as 1.5 × 10-7Ω. cm2and 1.2 × 10-7Ω . cm2for n+and p+contacts, respectively. These values are the lowest contact resistivities which have been achieved experimentally to date. We found no measurable metal-silicon interdiffusion when e-beam sintering was used. Electron-beam-induced MOS damage, including neutral traps, can be removed by a forming gas anneal.

Patent
01 Jul 1983
TL;DR: In this paper, a titled material is defined as a sliding contact material wherein 0.5-5wt% total of >= 1 kind among B, Si, Ge, Tl, and Tl are added to german silver without changing the compsn ratios thereof.
Abstract: PURPOSE:To provide a sliding contact material of german silver which is suppressed of oxidation, is stabilized to low contact resistance and is improved in consumption resistance by contg. limited compsn. contents of B, Si, Ge, Tl, etc. in german silver. CONSTITUTION:A titled material is a sliding contact material wherein 0.5-5wt% total of >=1 kind among B, Si, Ge, Tl are added to german silver without changing the compsn. ratios thereof. With addition of elements such as the above- mentioned B, Si, Ge, Tl, and the like which are harder to oxidize than Cu, the oxidation of Cu is suppressed, and the increasing and unstabilizing of contact resistance by the oxide of Cu are prevented. Further, consumption resistance is improved by said addition. The reasons for limiting the total content of >=1 kind among the above-mentioned B, Si, Ge, Tl lie in that if below 0.5%, there is no effect of the addition and at >=5%, the spring characteristic of the brush wire material to be made from the sliding contact material is deteriorated.

Patent
18 Aug 1983
TL;DR: An electrode material for semi-conductor device such as solar cells comprises Ag powders, at least one metal of Zironium, hafnium, vanadium, niobium, and tantalum, an organic binder, and an organic solvent, and, if necessary, Pd powders and Pt powders as discussed by the authors.
Abstract: An electrode material for semi-conductor device such as solar cells comprises Ag powders, at least one metal of zironium, hafnium, vanadium, niobium, and tantalum, an organic binder, and an organic solvent, and, if necessary, glass, Pd powders and Pt powders. The electrodes are prepared from the electrode material by printing, drying and firing at a low temperature and have a low contact resistance without any junction breakage or increase in leak current.

Journal ArticleDOI
Morton Antler1
TL;DR: In this paper, the fretting of palladium contacts was studied at conditions similar to those which occur in separable electronic connectors, and it was found that frictional polymers which form on their surfaces in ordinary room air can cause contact resistance to increase to unacceptable levels.
Abstract: The fretting of palladium contacts was studied at conditions similar to those which occur in separable electronic connectors. It was found that frictional polymers which form on their surfaces in ordinary room air can cause contact resistance to increase to unacceptable levels. The effect is dependent on wipe distance, becoming greater with increasing length, and is especially bad at the ends of the wear track. Contact resistance is less variable when fluid contact lubricants are used. Although the volume of polymer which forms increases when lubricant is present, the polymers are nonadherent and tend to be dispersed even when small amounts of fluid are used. A solid lubricant was found to be ineffective in stabilizing contact resistance. Fluid lubricant coatings, therefore, may provide some relief from the contact resistance problems of frictional polymerization when palladium and other catalytically active materials are used in sliding applications. Presented at the Eleventh International Conference on ...

Patent
14 Jul 1983
TL;DR: In this paper, a blade for cleaning toner from a liquid developed imaging surface comprises a body of high conductivity formed of rubber impregnated with carbon particles and a tip contacting the imaging surface formed of an inherently conductive rubber of lesser conductivity, the liquid developer affecting the conductivity of the body but not that of the tip, and the tip being replaceably inserted in a cooperating re-entrant cavity of large surface area formed in the body to provide a low contact resistance there.
Abstract: A blade for cleaning toner from a liquid developed imaging surface comprises a body of high conductivity formed of rubber impregnated with carbon particles and a tip contacting the imaging surface formed of an inherently conductive rubber of lesser conductivity, the liquid developer affecting the conductivity of the body but not that of the tip, and the tip being replaceably inserted in a cooperating re-entrant cavity of large surface area formed in the body to provide a low contact resistance therebetween.


Patent
12 Mar 1983
TL;DR: In this article, the authors proposed a method to prevent the increase of series resistance and thus change the electrode used for a solar battery, etc. into an electrode of high conversion efficiency by a method wherein said electrode is formed in the composite layer structure of a layer of low contact resistance with a semiconductor and a layer with low specific resistance.
Abstract: PURPOSE:To prevent the increase of series resistance and thus change the electrode used for a solar battery, etc. into an electrode of high conversion efficiency by a method wherein said electrode is formed in the composite layer structure of a layer of low contact resistance with a semiconductor and a layer of low specific resistance. CONSTITUTION:The electrode 6 is formed by means of the composite structure of the first layer 7 made of conductive paste containing carbon that shows low contact resistance with silicon as the layer contacting an a-Sin layer 5 and the second layer 8 made of conductive paste containing only a metal thereon. Ag, Cu, Au, etc. is used as the metal contained in the paste; the seat resistance of the layer 7 is set at 10 OMEGA/? or less, and the seat resistance of the layer 8 at 10OMEGA/? or less in order to decrease resistance loss in the course of conduction. When it is used for the solar battery, the series resistance loss of the electrode reduces, resulting in the enhancement of the conversion efficiency, since the first layer 7 has low contact resistance with Si and the seat resistance of the second layer 8 containing Ag as the main component is low.

Patent
Hans S. Rupprecht1, Sandip Tiwari1
30 Jun 1983
TL;DR: In this article, the first-to-form germanide of the refractory metal was formed by evaporating germanium and a refractive metal selected from the group consisting of molybdenum, tungsten and tantalum on the surface of an n-type gallium arsenide substrate.
Abstract: This invention relates generally to ohmic contacts to substrates made of III-V compounds and to a process for fabricating such contacts. More specifically, the invention is directed to a contact to gallium arsenide having a given level of n-type dopant therein, a region of the substrate doped with germanium and a layer of a germanide of a refractory metal selected from the group consisting of molybdenum, tungsten and tantalum disposed on the substrate. Still more specifically, the invention relates to an ohmic contact to gallium arsenide which includes an interface region of germanium heavily doped with arsenic disposed between the region doped with germanium and the layer of germanide. The contact is formed by evaporating germanium and a refractory metal selected from the group consisting of molybdenum, tungsten and tantalum on the surface of an n-type gallium arsenide substrate and sintering the substrate in a reducing atmosphere for a time and at a temperature sufficient to form the first-to-form germanide of the refractory metal. The resulting contact is stable, has a very low contact resistance and may be subjected to later high temperature processing steps without affecting its characteristics.

Patent
02 Sep 1983
TL;DR: In this article, a powder mixture consisting of 0.3-6% graphite, 5-45% Ni, 0.2-7% metallic oxide which is stable at a sintering temp. in a reducing atmosphere and the balance Ag is molded.
Abstract: PURPOSE:To obtain a contact material maintaining its low contact resistance and superior welding resistance and having superior resistance to consumption due to arc by simultaneously adding Ni and a metallic oxide which is stable at a sintering temp. in a reducing atmosphere to an Ag-graphite material and sintering them in a liq. phase. CONSTITUTION:A powdered mixture consisting of, by weight, 0.3-6% graphite, 5-45% Ni, 0.2-7% metallic oxide which is stable at a sintering temp. in a reducing atmosphere and the balance Ag is molded. The molded body is sintered in a liq. phase at a temp. from the m.p. of Ag, i.e. 960 deg.C to about 1,200 deg.C in a reducing atmosphere. Thus, a favorable contact causing no blister is obtd. This contact has stable and low contact resistance, and it is superior to an Ag-Ni contact in welding resistance and superior to an Ag-graphite contact in resistance to consumption due to arc.

Patent
25 Mar 1983
TL;DR: In this article, a logging tool with electrodes for introducing a current into a downhole formation and detecting a voltage produced in the formation by the current is presented, where the electrodes are equidistantly spaced but adjustable (either on a single logging tool or as between different logging tools).
Abstract: An apparatus includes a logging tool having electrodes for introducing a current into a downhole formation and for detecting a voltage produced in the formation by the current. The current is provided by a transmitter circuit, and the voltage is received and processed by a receiver circuit including a computer programmed to provide induced polarization and resistivity measurements based on the detected voltage. The electrodes are equidistantly spaced but are adjustable (either on a single logging tool or as between different logging tools) so that various logging runs can be made to obtain different measurements whereby the intrinsic complex resistivity (induced polarization) of formation layers can be suitably resolved. The apparatus also includes a contact resistance measurement circuit for making measurements used by another computer means to determine the contact resistance of each of the electrodes. The contact resistance measurements are used to compute the coupling phase angles for correcting the data at the output of the initial computer means. The logging tool is constructed to reduce water, and therefore electrical, leakage.

Journal ArticleDOI
TL;DR: In this article, a thermal conductivity cell is described which can be used to measure the bulk thermal conductivities and the thermal contact resistance of paper and other thin-film materials.
Abstract: A new thermal conductivity cell is described which can be used to measure the bulk thermal conductivity and the thermal contact resistance of paper and other thin‐film materials. The cell incorporates a hydraulic piston which can apply pressures up to 1700 psi to the sample which is situated between the optically flat end faces of two brass columns. By measuring the thermal resistance of paper samples of various thicknesses, it is demonstrated that a pressure of 1700 psi effectively eliminates the thermal contact resistance. By comparing measurements at zero and maximum applied pressure, both the bulk conductivity and the contact resistance can be calculated. This is illustrated with several types of paper. In all cases, there is a qualitative correlation between the measured contact resistance and the surface roughness of the sheet. The technique can also be used for thin polymer films, and for layered structures such as the ink donor films used in thermal transfer printing.

Journal ArticleDOI
J.M. Ford1
TL;DR: In this article, the specific contact resistivities of Al/polysilicon interfaces were determined using an extrapolation method, and measurements were taken both before and after an anneal cycle of 20 min at 450°C in forming gas.
Abstract: Experimental results on the specific contact resistivity of Al/polysilicon are given for Al/1.5-percent Si contacting poly Si implanted with boron or phosphorus, annealed to surface concentrations from 3E18 to 4E20 cm-3. Specific contact resistivities of the interfaces involved were determined using an extrapolation method. Measurements were taken at room temperature, and were conducted both before and after an anneal cycle of 20 min at 450°C in forming gas. Results provide a useful parameter which enables modeling of Al/poly Si contacts.

Journal ArticleDOI
C.-Y. Su1, C. Stolte1
TL;DR: In this paper, the contact resistance of nonalloyed metal contacts to Zn-implanted shallow (∼1000 A) p+ GaAs layers was investigated, achieving contact resistance as low as 9×10−7 Ωcm2.
Abstract: Contact resistance of nonalloyed metal contacts to Zn-implanted shallow (∼1000 A) p+ GaAs layers was investigated. Contact resistance as low as 9×10−7 Ωcm2 was achieved for evaporated Ti/Pt/Au contacts to Zn 40 keV and Zn 100 keV double-implanted layers with a peak concentration of 7×1019/cm3.