Showing papers on "Van der Pauw method published in 1986"
TL;DR: In this paper, van der Pauw measurements, C-V measurement, and secondary ion mass spectrometry were used to study the rapid diffusion of Be in heavily doped GaAs epilayers grown by MBE.
Abstract: van der Pauw measurements, C‐V measurement, and secondary ion mass spectrometry were used to study the rapid diffusion of Be in heavily doped GaAs epilayers grown by MBE. The concentration dependence of the Be diffusion was measured. A discrepancy exists at high doping level between our experimental results and the Be interstitial‐substitutional diffusion model previously proposed. The threshold of fast Be diffusion versus doping concentration was determined and a diffusion coefficient as high as 2×10−12 cm2/s was observed at 600 °C. A surface Fermi‐level pinning effect model has been proposed in addition to the interstitial‐substitutional model, which has successfully explained the onset of fast Be diffusion in MBE‐grown GaAs at high doping level.
63 citations
TL;DR: In this paper, the van der Pauw method was used to measure the temperature dependence of Hall mobility, carrier (hole) concentration, and conductivity of a p-type ZnSe crystal.
Abstract: Electrical properties of a low‐resistive and stable p‐type ZnSe crystal grown by the temperature difference method under controlled vapor pressure are reported. The temperature dependence of Hall mobility, carrier (hole) concentration, and conductivity are measured by the van der Pauw method. Hole mobility appears to be about 200 cm2/V s at 100 K and about 50 cm2/V s at 300 K. The activation energy of a shallow acceptor impurity is also determined to be 70–85 meV.
55 citations
TL;DR: In this paper, a multilayer structure consisting of alternating undoped and heavily boron-doped regions was fabricated in situ and the interlayer doping profiles of these structures, as determined by secondary ion mass spectroscopy, are abrupt.
Abstract: Limited reaction processing was used to deposit ultrathin, highly doped layers of epitaxial silicon. Multilayer structures consisting of alternating undoped and heavily boron‐doped regions were fabricated in situ. The interlayer doping profiles of these structures, as determined by secondary ion mass spectroscopy, are abrupt. Van der Pauw measurements indicate that the electrical characteristics of the p+ epitaxial films are comparable to bulk material.
45 citations
TL;DR: Hall effect measurements have been carried out in the diamond anvil cell to pressures of 6 GPa as mentioned in this paper, where a plasma sprayed coating has been used to insulate the electrical leads from the gasket, similar to the configuration employed by Tozer and King.
Abstract: Hall effect measurements have been carried out in the diamond anvil cell to pressures of 6 GPa. A plasma sprayed coating has been used to insulate the electrical leads from the gasket, similar to the configuration employed by Tozer and King [Rev. Sci. Instrum. 56, 260 (1985)], but a van der Pauw geometry was used to make the Hall and mobility measurements. Application of the technique to GaAs at 300 K is described, for which the Γ‐X conduction band crossover is observed at 4.0 GPa, in good agreement with recent photoluminescence measurements.
28 citations
TL;DR: The structural and electrical properties of a Nb-Si thin alloy film as a function of temperature have been studied by Auger electron spectrometry, Rutherford backscattering spectroscopy, transmission electron microscopies, and in situ electrical resistivity and Hall coefficient measurements.
Abstract: The structural and electrical properties of a Nb-Si thin alloy film as a function of temperature have been studied by Auger electron spectrometry, Rutherford backscattering spectroscopy, transmission electron microscopies, and in situ electrical resistivity and Hall coefficient measurements. The NbSi2,8 films were deposited by double electron-gun coevaporation onto oxidized silicon. For electrical measurements samples of a van der Pauw pattern were made through metallic masks. In the as-deposited state the coevaporated alloy film was amorphous. Upon annealing a precipitous drop in resistivity near 270°C has been determined to be the amorphous to crystalline phase transformation. The kinetics of the transformation has been determined by isothermal heat treatment over the temperature range of 224°C to 252°C. An apparent activation energy of 1.90 eV has been measured. The nucleation and growth kinetics in the crystallization process show a change in the power of time dependence from 5.5 to 2.4. The microstructures of films at various states of annealing have been correlated to the resistivity change. The crystalline NbSi2 shows an anomalous metallic behavior. The resistivity (p) versus temperature curve has a large negative deviation from linearity (dfl) and it approaches a saturation value (p
sat) as temperature increases. The resistivity data are fitted by two empirical expressions put forth to explain the resistivity behavior in A15 superconductors at low and high temperatures. One is based on the idea that ideal resistivity must approach some limiting value in the regime where the mean free path becomes comparable to the interatomic spacing and the other is based on a selective electron-phonon assisted scattering. In spite of the wide temperature range of analysis, it is not possible to choose one of them due to the fact that the best fit in both cases is nearly the same. The Hall coefficient (R
H) changes sign from negative above ∼250°K to positive below ∼ 250°K.
26 citations
TL;DR: In this paper, a novel photochemical method for liquid-phase deposition of metal films is described, in which a metal containing compound and a metal-metal bonded carbonyl complex are dissolved together in a polar solvent and the mixture is irradiated using a UV laser.
Abstract: A novel photochemical method for liquid-phase deposition of metal films is described. In the liquid phase deposition scheme, a metal containing compound and a metal-metal bonded carbonyl complex are dissolved together in a polar solvent and the mixture is irradiated using a UV laser. The optical arrangement consists of a HeCd laser which provides 7 mW of power at a wavelength of 325 nm in the TEM(OO) mode. The beam is attenuated and may be expanded to a diameter of 5-20 mm. Experiments with photochemical deposition of silver films onto glass and quartz substrates are described in detail. Mass spectrometric analysis of deposited silver films indicated a deposition rate of about 1 A/s at incident power levels of 0.01 W/sq cm. UV laser-induced copper and palladium films have also been obtained. A black and white photograph showing the silver Van Der Pauw pattern of a solution-deposited film is provided.
21 citations
TL;DR: In this paper, four different Co-silicide compounds were obtained by solid-state reaction at 800 °C in thin bilayers of amorphous silicon and cobalt evaporated on SiO2 substrates.
Abstract: Four different Co‐silicide compounds were obtained by solid‐state reaction at 800 °C in thin bilayers of amorphous silicon and cobalt evaporated on SiO2 substrates. Rutherford backscattering spectroscopy (2 MeV 4He+), x‐ray diffraction, and Auger electron spectroscopy were used to obtain information about the chemical and crystallographic characteristics of the samples. Results indicate that in each sample only one of the following phases is present: CoSi2, CoSi, Co2Si, and Co4Si, the latter identified on the basis of the stoichiometric ratio only. Electrical resistivity and Hall effect measurements on van der Pauw structures were carried out as a function of the temperature in the intervals: 10–1000 and 10–300 K, respectively. At room temperature the resistivity ranges from the value 19 μΩ cm for CoSi2 to the value 142 μΩ cm for CoSi. There are some analogies with the case of a classical metal, but remarkable differences are also detectable in the resistivity versus temperature behavior and in the order ...
17 citations
TL;DR: In this paper, the authors reported the successful use of the Hg1−xCdxTe native oxide as an encapsulation layer for an annealing process designed to activate an implanted impurity.
Abstract: We report for the first time the successful use of the Hg1−xCdxTe native oxide as an encapsulation layer for an annealing process designed to activate an implanted impurity. The annealing process does not require Hg over pressure and consists of both furnace (∼200 °C) and rapid thermal (∼320 °C) anneals. Using 2.2 MeV 4He+ ion channeling measurements, we show that the implantation damage can be annealed out without loss of Hg from the substrate. Also, both secondary ion mass spectrometry and differential van der Pauw measurements indicate that the resulting electron concentration profile closely matches that of the implanted 11B profile and the electrical junction is found to lie close to the expected position of the metallurgical junction.
14 citations
TL;DR: Pulsed electron beam annealing of phosphorus-implanted CuInS2 has been found to be an efficient method in p • type doping of CuIn S2 as discussed by the authors, and effective carrier concentration profiles have been determined with a maximum carrier concentration of 9×1019 cm−3.
Abstract: Pulsed electron beam annealing of phosphorus‐implanted CuInS2 has been found to be an efficient method in p‐type doping of CuInS2. A sheet resistance as low as 10.1 Ω/⧠, a sheet carrier concentration as high as 2.6×1016 cm−2, and a hole mobility as high as 499 cm2/V s have been obtained. The irradiation energy density for the best doping condition was determined to be in the range ∼11–13 J/cm2. Using Van der Pauw/Hall technique in conjunction with a chemical etching technique, effective carrier concentration profiles have been determined with a maximum carrier concentration of 9×1019 cm−3. Excellent p‐n CuInS2 homojunctions have been fabricated by electron beam pulse annealing with an ideality factor of 1.75.
14 citations
TL;DR: In this paper, the van der Pauw method was extended to a system consisting of a square four-point probe array on a rectangular parallelepied and the geometrical correction factor for the resistivity of semiconductors was derived.
Abstract: The geometrical correction factor for the resistivity of semiconductors is derived for a system consisting of a square four-point probe array on a rectangular parallelepied. The van der Pauw method requires the geometrical correction factor for samples with a thickness greater than about 35% of the probe separation. Numerical evaluations are given as a function of the size of the rectangular parallelepiped and the probe configuration.
11 citations
IBM1
TL;DR: In situ resistivity measurement was used to study the crystallization and the electrical conduction processes of V3Si and VSi2 thin films as a function of temperature.
TL;DR: In this article, the characteristics of thin films of Ta-Cu, prepared over a wide range of compositions by cosputter deposition onto GaAs and fused quartz substrates, are studied by X-ray diffraction and van der Pauw resistivity measurement.
Abstract: The characteristics of thin films of Ta-Cu, prepared over a wide range of compositions by cosputter deposition onto GaAs and fused quartz substrates, are studied by X-ray diffraction and van der Pauw resistivity measurement. Results show films to be amorphous over the range of 55-95 at. pct, and show Ta(93)Cu(7) barriers to be effective in preventing Au in-diffusion, with a 3000-A layer remaining unpenetrated after an annealing at 700 C for 20 min. Diffusion of Ga and/or As into amorphous 93 at. pct Ta is found to be more rapid than that of Au, and interfacial reactions were shown to form compounds including Ta3Au, CuAu, TaAs2, and Ga3Cu7 above 700 C.
TL;DR: In this paper, a four-point dc-resistance measurement apparatus was used to obtain the temperature dependence of the ratio of two components of the resistivity tensor of samples with hexagonal structure.
Abstract: We report on a four‐point dc‐resistance measurement apparatus to obtain the temperature dependence of the ratio of two components of the resistivity tensor of samples with hexagonal structure. We point out that this ratio, as well as the individual components, can be calculated. Problems arise for thin crystals having a small anisotropy. These can be solved by performing a resistance measurement with the technique of van der Pauw on the same sample. The achieved relative accuracy in the temperature‐dependent anisotropy ratio is better than 1%. The absolute accuracy depends on the nonuniformity of the crystal thickness, and the determination of probe distances.
TL;DR: In this article, a new technique for silicon epitaxial growth using mercury-sensitized photochemical vapor deposition (photo-CVD) was developed using a high-energy electron diffraction (RHEED).
Abstract: A new technique for silicon epitaxial growth has been developed using mercury-sensitized photochemical vapor deposition (photo-CVD). Epitaxial thin layers were grown on (100) Si substrates at 100–300°C from a gas mixture of Si2H6+SiH2F2+H2 by irradiation of a low pressure mercury lamp (1849A, 2537A). Reflective high energy electron diffraction (RHEED) and Raman scattering measurements showed that the epitaxial layers had good crystallinities.The epitaxial layers were characterized by secondary ion mass spectroscopy (SIMS) and the van der Pauw Hall measurements. The undoped Si layer showed the electron mobility of 520cm2/Vs with a carrier concentration of 3.2×1014 cm−3.
TL;DR: In this article, a vertical cold-wall low-pressure metalorganic chemical vapor deposition system is used for the growth of Sn-doped n-type GaAs epilayers Smooth and specular Sndoped GaAs Epilayers can be easily grown Van der Pauw Hall measurement, and I•V and C•V characteristics show that tetraethyltin is a suitable source for GaAs n−type dopant Sn surface accumulation.
Abstract: A vertical cold‐wall low‐pressure metalorganic chemical vapor deposition system is used for the growth of Sn‐doped n‐type GaAs epilayers Smooth and specular Sn‐doped GaAs epilayers can be easily grown Van der Pauw Hall measurement, and I‐V and C‐V characteristics show that tetraethyltin is a suitable source for GaAs n‐type dopant Sn surface accumulation has been observed from Auger electron specroscopy (AES) and secondary ion mass spectrometry (SIMS) measurements From infrared spectroscopy (IR) examination of the deposit on the quartz reactor wall, the decomposition of TEG is incomplete The results of selective epitaxial growth indicate that the GaAs growth from TEG is controlled by surface kinetics Tetraethyltin can enhance the growth rate of GaAs and decrease the As/Ga ratio and also EL2 concentration A EL2 model is proposed
TL;DR: In this article, two-terminal magnetoresistance measurements on a short gated GaAs-AlGaAs HEMT (High Electrical Mobility Transistor) sample for magnetic fields to 185 Telsa and temperatures near 05 K were reported.
TL;DR: Shubnikov-De Haas and Van der Pauw measurements at 4.2 K are presented for the two-dimensional electron gas in a selectively doped GaInAsInP heterostructure grown by MBE.
TL;DR: In this article, the electron mobility in InSb has been measured at 77-380 K using the van der Pauw method and the experimental values were compared with the theoretical values obtained by an iteration technique.
Abstract: The electron mobility in InSb has been measured at 77-380 K using the van der Pauw method. The experimental values were compared with the theoretical values obtained by an iteration technique. In the intrinsic region (T>250 K), the theoretical values were found to agree with the experimental values if the acoustic deformation potential constant, E1 was chosen to be 14 eV.
TL;DR: In this article, the authors used the Molecular Beam Epitaxial (MBE) technique to study surface structure, single crystallinity and electrical properties of Pb1-x SnxTe (LTT) films.
Abstract: Epitaxial films of Pb1-x SnxTe (LTT) were deposited on (100) KCI substrates at 300, 325 and 350C using Molecular Beam Epitaxial (MBE) technique. RHEED, X-ray and Van der Pauw techniques were employed to study surface structure, single crystallinity and electrical properties of these films respectively. The resistivity of these films was found to decrease from 10−2 Ω-cm at 300K to 10−3 Ω-cm at 100 K. The mobility was found to increase with lowering of temperature in the range 102 cm3/V sec at 300 K and 103 cm2/Vsec at 100 K.