Showing papers on "Van der Pauw method published in 1981"
TL;DR: In this article, the influence of source Ga-In-As melt baking temperatures on the epitaxial layer purity was investigated and the results of a photoluminescence study and van der Pauw measurements showed that acceptor impurities as well as donor impurities can be excluded from the source solution by a suitable heat treatment.
Abstract: Liquid phase epitaxy (LPE) and the properties of high purity GaInAs layers on (100)InP substrates are reported. Low carrier concentration (3.8–5.4×1014 cm-3) and high electron mobility (47000–51000 cm2/V.s at 77 K) were obtained reproducibly. The influence of source Ga-In-As melt baking temperatures on the epitaxial layer purity was investigated. The results of a photoluminescence study and van der Pauw measurements show that acceptor impurities as well as donor impurities can be excluded from the source solution by a suitable heat treatment.
35 citations
TL;DR: In this article, a p+n-n--n junction is formed for Zn and Cd diffusion in (100) n-InP single crystals, carried out using Zn3P2 and Cc3P 2 sources, when the background carrier density is lower than 1016 cm-3.
Abstract: This letter reports on studies of Zn and Cd diffusion in (100) n-InP single crystals, carried out using Zn3P2 and Cd3P2 sources. When n-InP background carrier density ND is lower than 1016 cm-3, two diffusion fronts are observed and a p+-n--n junction is formed for Zn and Cd diffusion. A p+-n one-sided abrupt junction is formed when ND is 1016–1017 cm-3. The carrier density profiles were observed through EBIC measurement, van der Pauw method, C-V measurement using a Schottky barrier contact, and diffusion velocity dependence on n-InP background carrier density.
29 citations
TL;DR: In this paper, the characteristics of PbTe films grown by molecular beam epitaxy (MBE) have been investigated, and the results suggest the need for a buffer layer in a laser structure.
Abstract: The characteristics of PbTe films grown by molecular beam epitaxy (MBE) have been investigated. These films were grown on (100) oriented Tl-doped PbTe substrates under UHV conditions (~5×l0−9 Torr during deposition). Substrate surface contamination levels were studied with Auger electron spectroscopy. Oxygen, the dominant impurity observed, is rapidly thermally desorbed from PbTe, but is stable on Pb1−xSnxTe up to at least 410°C. Carrier concentration and mobility were measured with the Van der Pauw technique. The electron mobility increased strongly with increasing film thickness, varying from 4,000 to 14,000 cm2/volt-sec as the thickness increased from 2.0 to 7.3 µn. The film surface also became smoother with increasing film thickness. These results suggest the need for a buffer layer in a laser structure. Lasers grown with 6 μm thick buffer layers have exhibited extremely low threshold current densities (40 A/cm2 at 13 K) and very high junction resistancearea products at zero-bias (0.7 Ω−cm2 at 77 K), indicative of very high junction quality.
24 citations
TL;DR: In this article, the epitaxial growth of lattice matched In 0.53 Ga 0.47 As on InP substrates has been investigated using optical microscopy, X-ray diffraction, photoluminescence and van der Pauw analysis.
19 citations
TL;DR: In this paper, a new open-flow vapour phase process was reported for the epitaxial growth of cadmium mercury telluride on to substrates of CdxHg1-xTe. The layers were characterised by in-depth profiling using secondary ion mass spectrometry and also the electrical properties have been assessed using the van der Pauw technique.
Abstract: A new open-flow vapour phase process is reported for the epitaxial growth of cadmium mercury telluride on to substrates of cadmium telluride. The layers have been characterised by in-depth profiling using secondary ion mass spectrometry and also the electrical properties have been assessed using the van der Pauw technique. Material with x values in CdxHg1-xTe ranging from 0 to 0.5 have been grown at approximately 410 degrees C.
19 citations
TL;DR: In this paper, a rigorous derivation is given to generalize the allowed, Hall effect, sample shapes from the restrictive, rectangular parallelepiped configurations to a much more general class of geometries characterized by mirror symmetry for materials whose mobile carriers have surfaces of constant energy in k space that are well described by ellipsoids.
Abstract: A rigorous derivation is given to generalize the allowed, Hall effect, sample shapes from the restrictive, rectangular parallelepiped configurations to a much more general class of geometries characterized by mirror symmetry for materials whose mobile carriers have surfaces of constant energy in k space that are well described by ellipsoids. However, this mirror symmetry condition is more restrictive than the almost arbitrary sample shapes proposed with the van der Pauw technique for thin films. Experimental data taken on n‐type CdS at liquid‐nitrogen temperatures in magnetic field strengths of 8 and 145 kG show that errors ranging from 1 to 600% can result from van der Pauw‐type geometries depending on how much the sample shape and/or contact arrangement differs from the mirror symmetry. An empirically derived averaging technique is described that reduces the observed errors to less than 13% even with van der Pauw‐type shapes that do not meet the mirror symmetry conditions.
14 citations
TL;DR: In this article, the energy levels and the degeneracy ratios for chromium in silicon have been determined by the van der Pauw method using the curve fitting method for carrier concentration based on the charge balance equation with the root mean square deviation.
Abstract: The energy levels and the degeneracy ratios for chromium in silicon have been determined by the Hall coefficients which were measured by the van der Pauw method. Using the curve fitting method for carrier concentration based on the charge balance equation with the root mean square deviation, the analysis shows that chromium in silicon gives rise to two donor levels. The energy levels of the upper and lower donors are located at Ec-0.226(±0.010)eV and Ev+0.128(±0.005)eV, and their degeneracy ratios are 1 3 and 1 4 , respectivel
10 citations
TL;DR: The thermodynamics and kinetics of copper transport in bornite (Cu5FeS4) have been investigated in this article, where the van der Pauw technique was used to obtain the electronic conductivity (σe) as a function of temperature.
5 citations
TL;DR: In this paper, an automated system for dark conductivity and Hall measurements and photoconductivity and photo-Hall characterization of high resistivity semiconductors is described, which has been applied to commercially available semi-insulating GaAs substrates.
Abstract: An automated system for dark conductivity and Hall measurements and photoconductivity and photo‐Hall characterization of high resistivity semiconductors is described. This system has been applied to commercially available semi‐insulating GaAs substrates.
4 citations
11 Jun 1981
TL;DR: In this article, it is shown by optical absorption data that the composition of films can be changed from x = 0.1 to 0.27 by changing the relative percentages of HgTe and CdTe particles in sputtering targets, made by cold-pressing a homogenized mixture of these particles.
Abstract: The advantages of r.f. triode sputtering in a Hg atmosphere for deposition of (Hgl-xCdx)Te thin films for low-cost photoconductor and ohotovoltatic infrared detector arrays on electronically-active Si substrates are discussed. It is shown by optical absorp-tion data that the composition of films can be changed from x = 0.1 to 0.27 by changing the relative percentages of HgTe and CdTe particles in sputtering targets, made by cold-pressing a homogenized mixture of these particles. Changes in the physical topography and composition of the surface of pressed-powder targets when bombarded with Hg are described. The mobility and implied carrier concentrations at 24 and -188°C of n and p-type films with different compositions in the 0.18 < x <0.27 range were measured by the Van der Pauw technique. The films were deposited under different sputtering conditions onto high resistivity CdTe and Si substrates with (111) surface orientation. The film properties were improved by post-deposition annealing in a Hg atmosphere using a two-zone furnace. An increase in electron mobility of n-type films to values up to 17 and 50 percent of those for bulk material at -188 and 24°C respectively were obtained using unoptimized annealing parameters.© (1981) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
1 citations
TL;DR: In this article, the annealing behavior of antimony implanted LPCVD polysilicon was investigated and it was shown that the sheet resistance of the films is controlled by dopant segregation at grain boundaries and the fraction of ants distributed on active sites within individual grains.
Abstract: Rutherford backscattering, Van der Pauw and TEM measurements were used to characterise the annealing behaviour of antimony implanted LPCVD polysilicon. High electrical activity without dopant redistribution was obtained for 600°C annealing of 1 × 1015 cm−2 and 3×1015 cm−2 antimony implanted samples. Subsequent annealing at temperatures ≥900° C resulted in considerable grain-boundary-assisted redistribution of antimony within the polycrystalline layers and associated changes in sheet resistance. Our results suggest that the sheet resistance of the films is controlled by dopant segregation at grain boundaries and the fraction of antimony distributed on active sites within individual grains.