InSb Single Crystals Research Articles

Changes of the growth morphology in insb crystals pulled under the presence of ultrasonic vibrations

AbstractIn the Czochralski method, the effect of ultrasonic vibrations on the growth of InSb single crystals was investigated by observing the growth morphology. Remarkable changes which ultrasonic vibrations brought about were: (1) the crystal diameter, (2) the width of the facet region and (3) the inclined angle of non‐facet interfaces near the facet region for the (111) plane. After introducing vibrations, the crystal diameter decreased smoothly with growth time. However, both the facet width and the inclined angle reached each minimum value after 5 to 7 min regardless of the magnitude of vibrational output powers from 30 to 90 W, and they were in roughly proportional relation with each other. The change rates of crystal diameter and of facet width increased with vibrational powers. The decrease of crystal diameter was known to result from the rise of the melt temperature, which was brought by both the mixture of the melt and the thermal energy transformation due to ultrasonic vibrations. The change of facet width depended upon the melt flow itself in addition to the temperature rise.

Programming of crystal diameter in Czochralski growth by a cooling plot: Application to InSb

It is shown, that under thermal “stiffness” conditions, the dimensions of a crystal grown by the Czochralski method may be programmed by a cooling plot. The cooling plot is calculated from the measured longitudinal and radial thermal gradients, involving also the melt-to-solid densities ratio. Utilization of the principle could save the need for sophisticated expensive automatic diameter control systems. In the present work the principle was successfully applied to the growing of InSb single crystals of diameters around 2cm.

Radiation damage in InSb single crystals by α-particle bombardment

Helium ions with energies of 50 keV and 2 MeV have been implanted in InSb single crystals at different temperatures. The resultant radiation damage was analysed using proton and α-particle channeling. Implantations at room temperatures with moderate doses produce appreciable defect concentrations which cannot completely be removed by isochronal annealing even at temperatures just below the melting point. The shape and energy dependence of the channeling spectra suggest that dislocations are mainly responsible for the observed dechanneling. A systematic study of the influence of the implantation temperature reveals, furthermore, a rather narrow temperature region where defect production is strongly reduced. At temperatures above this region no radiation damage by α-particle irradiation is detectable. Apparently the mobilities of the primary point defects created in the collision cascade are strongly enhanced above this temperature, preventing the formation of stable defect configurations.

Negative magnetoresistance in heavily doped and compensated n‐type InSb

AbstractTransverse magnetoresistance measurements are made on heavily doped n‐type InSb single crystals in the temperature range 77 to 300 K. The magnetoresistance at low temperatures is found to be negative indicating a contribution of impurity band conduction to the electrical transport phenomenon. The conductivity and Hall mobility measurements also provide evidence of impurity band conduction near liquid nitrogen temperature. The mobility of the charge carriers in the impurity band is estimated from the experimentally observed mobility.

Electron microscopic investigation of the nature of the dislocation loops created by electron irradiation (2 MeV) between room temperature and 200°C in InSb single crystals

Electron microscopic investigation of the nature of the dislocation loops created by electron irradiation (2 MeV) between room temperature and 200°C in InSb single crystals

GALVANOMAGNETIC PROPERTIES OF PLASTICALLY DEFORMED InSb

n and p type InSb single crystals with as low as available initial carrier concentrations and dislocation densities were deformed by torsion or uniaxial compression. Hall effect and conductivity measurements exhibit a large decrease of the free carrier concentration and their mobilities for edge dislocations when the ratio between the carrier concentration and the dislocation density is not too high. Screw dislocations have been seen to inverse the type of the as-grown material for n-type InSb. Results are discussed in terms of position, occupation rate and localization of energy states introduced in the band gap.

Observation of defects in an InSb single crystal by neutron topography

Crystal Research and TechnologyVolume 18, Issue 7 p. K65-K67 Short Note Observation of defects in an InSb single crystal by neutron topography Dipl.-Ing. B. Chalupa, Dipl.-Ing. B. Chalupa Nuclear Physics Institute, ČSAV 25069 Řež near Prague, CzechoslovakiaSearch for more papers by this authorDr. sc. nat. R. Michalec, Dr. sc. nat. R. Michalec Nuclear Physics Institute, ČSAV 25069 Řež near Prague, CzechoslovakiaSearch for more papers by this authorB. Hašková, B. Hašková Nuclear Physics Institute, ČSAV 25069 Řež near Prague, CzechoslovakiaSearch for more papers by this authorJ. Vávra, J. Vávra Nuclear Physics Institute, ČSAV 25069 Řež near Prague, CzechoslovakiaSearch for more papers by this author Dipl.-Ing. B. Chalupa, Dipl.-Ing. B. Chalupa Nuclear Physics Institute, ČSAV 25069 Řež near Prague, CzechoslovakiaSearch for more papers by this authorDr. sc. nat. R. Michalec, Dr. sc. nat. R. Michalec Nuclear Physics Institute, ČSAV 25069 Řež near Prague, CzechoslovakiaSearch for more papers by this authorB. Hašková, B. Hašková Nuclear Physics Institute, ČSAV 25069 Řež near Prague, CzechoslovakiaSearch for more papers by this authorJ. Vávra, J. Vávra Nuclear Physics Institute, ČSAV 25069 Řež near Prague, CzechoslovakiaSearch for more papers by this author First published: 1983 https://doi.org/10.1002/crat.2170180724Citations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Citing Literature Volume18, Issue71983Pages K65-K67 RelatedInformation

Zone Melting Recrystallization of InSb Films on Oxidized Si Wafers

ABSTRACTInSb thin films on oxidized Si wafers have been recrystallized using a strip heater to generate and scan a narrow molten zone across the film. Grains up to 3 × 10 mm have been produced. Crystallization proceeds in a faceted cellular fashion, the excess solute (Sb) being rejected into subboundaries which often lie along low-index crystallographic directions. A InSb-Sb eutectic structure forms at the subboundaries. The width of the single-crystal InSb between subboundaries is approximately 75 μm. The techniques of planar constriction and subboundary entrainment have been extended to InSb for the selection of single grains and the orelocation of subboundaries. This technology of producing InSb thin films on oxidized Si substrates max, be extendable to other III-V materials, and could lead to novel device structures through the integration of Si and III-V compound devices on the same substrate.

Growth of highly homogeneous InSb single crystals

A characteristic detect, shaped like the letter “Y”, could be found in the [111] pulled InSb crystal. The carrier concentration in the defect is higher than in other parts, which is detrimental in MOS monolithic IR imaging devices. A high quality InSb single crystal for IR imaging devices was found to be grown by a pulling method using a seed inclined 5–10° from the [111] to the [110] direction. The growth conditions for homogeneous InSb single crystals were discussed.

Observation of effect of temperature on X-ray diffraction intensities across the InKabsorption edge of InSb

Variations at room and liquid-nitrogen temperatures have been observed of the energy-dispersive integrated X-ray reflection intensity from an InSb single crystal across the In K absorption edge by the use of a multi-channel solid-state detector. The results show that the relative intensities from a nearly perfect crystal change as a function of the temperature above and below the absorption edge, but there is no such change in a nearly mosaic crystal. This variation observed in a nearly perfect crystal is characteristic of an absorbing monatomic perfect crystal and can be explained in terms of the dynamical theory of diffraction including anomalous scattering.

Effect of Ultrasonic Vibrations on InSb Pulled Crystals

InSb single crystals were pulled from the melt by the Czochralski method. During the growth of the crystals, ultrasonic vibrations were introduced into the melt through the carbon crucible. The facet region at the center of the pulled crystals shifted to the periphery of the crystals and simultaneously decreased in size, because the ultrasonic vibrations stirred the melt and raised its temperature. Furthermore, the difference in the values of the spreading resistance between the facet and the off-facet regions also decreased. These results indicate that inhomogeneous distributions of impurity concentration in the crystals were improved by the introduction of ultrasonic vibrations.

Galvanomagnetic properties of plastically deformed InSb single crystals

The dc Hall effect, dc conductivity and mobility have been studied on deformed and undeformed samples ofn-type InSb from liquid nitrogen temperature to room temperature. These studies have shown that the Hall coefficient values of deformed samples do not differ much from undeformed sample, but a considerable amount of change was observed in mobility, suggesting that equal number of donor and acceptor type dislocations are introduced during the deformation process. In addition the mobility variation of the deformed samples with temperature has shown a peak in 170–300°K range. The dislocation mobility (μ D) is deduced from the observed mobilities of deformed and undeformed samples. The plotμ D vs T has two regions, region 1 being independent of temperature and region 2 having a linear increase with temperature. Theβ factor obtained from region 2 is found to be almost equal to the one calculated from Dexter and Seitz model. The dislocation densities at room temperature are also calculated for the deformed samples using the above model.

Homoepitaxial superlattices with nonoriented barrier layers

Stimulation possibilities of epitaxial film growth on amorphous and polycrystal layers covering the surface of the orienting substrate are shown. Multilayer periodical structures of superthin (L < 100 Å) single-crystal InSb or PbTe films alternating with nonoriented GaAs, C or Ge layers have been obtained and investigated.

ON THE FACETS AND TWIN FORMATION IN THE GROWTH OF InSb SINGLE CRYSTALS

The observations of solid-liquid interface morphology of InSb single crystals pulled by using various oriented seeds is described. Experimental results indicate that the external forms of crystals as well as the formation of growth twin are closely related to the development and properties of {111} facets on the solid growth surface. The various experimental phenomena can all be interpreted successfully according to a {111} plane octahedron or two-octahedron model of the zinc-blende structure.

ANOMALOUS IMPURITY SEGREGATION IN InSb SINGLE CRYSTALS

The impurity distributions on the cross-section of Te-doped and non-doped InSb single crystals are determined by means of Hall technique and mass-spectrum analysis. Results of measurements show clearly that the impurity segregation is anomalous on the facets. These phenomena are discussed in connection with the mechanism of the facet effect. An explicit expression based on thermodynamic considerations is derived and applied to explain the observed anomalous segregation phenomena.

Thermoelectric properties of indium antimonide under high pressure up to 35 kbar

The thermoelectric power α and relative resistivity R/Ro of InSb single crystals of n-type and p-type at 293 and 360 K are measured under pressure up to 35 kbar in various pressure transmitting liquids. The experimental data obtained at hydrostatic conditions have no anomalies. It is found also that α changes its sign from negative to positive for InSb samples of n-type under pressure at quasihydrostatic conditions. The pressure dependence of the resistivity for the same InSb samples has some anomalies, too. It is connected with the arising of inhomogeneous deformation in the sample at generating of pressure. It is supposed that inhomogeneous strains cause defects in crystal lattice which lead to appearance of the acceptor levels in the band structure of InSb. A change of the sign of α from negative to positive for pure InSb samples of p-type under pressure are in good agreement with the data of other authors. [Russian Text Ignored].

The defects in Se‐doped InSb single crystals

AbstractUsing optical microscopy and TEM methods as well as X‐ray topography method structural perfection of Czochralski grown Se‐doped InSb single crystals has been investigated. Se concentration was determined by mass‐spectrometry method and was in the range of 1.1017 to 9.1019 cm−3. – It has been shown that Se presence up to the highest concentration does not influence crystal dislocation structure, but gives rise to the large number of precipitates showing moiré contrast. The size of the precipitates is in the range of 0.5 μm to 3.8 μm. From the calculation of the contrast it has been grown that lattice parameter of the precipitates differs from that of matrix by 0.02 ÷ 0.05 Å. – Besides, in crystals with high Se concentration (9.1019 cm−3) small particles with symmetrical field of deformation appear.

GaSb and InSb crystals grown by vertical and horizontal travelling heater method

GaSb and InSb single crystals up to a length of 30 mm were grown by the Travelling Heater Method (THM) using a vertical system as well as a horizontal one. The maximum growth rate of inclusion-free 10 mm diameter crystals (GaSb: T = 500°C and InSb: T = 400°C) was 2.5 ± 0.5 mm/day. The influence of various growth parameters on the crystal quality was studied.

Compositionally modulated sputtered InSb/GaSb superlattices: Crystal growth and interlayer diffusion

Compositionally modulated single-crystal InSb/GaSb superlattice structures have been grown by multitarget sputtering in order to investigate the effects of film growth parameters on the defect structure, abruptness, and coherence of sputtered heterojunctions. The layer thicknesses studied ranged from 12 to 70 Å. The polycrystalline–to–single-crystal ’’transition temperature’’ Tc was found to decrease with decreasing average film-substrate lattice mismatch and modulation period, Λ. The Λ-dependence resulted from a decrease in the coherence between layers and the associated increased amount of plastically accommodated strain which occurred with increasing layer thickness. Increasing the film growth temperature TS and decreasing the period of the composition modulation also resulted in a decrease in the density of microtwins and low-angle dislocation boundaries which were observed in all films. Single and multiple {111} twins were identified. For a given set of growth conditions on cleaved BaF2 and NaCl substrates, a significant decrease in Tc and structural defect densities could be achieved by coating the substrates with thin (&amp;lt;300Å) single-crystal InSb layers which were deposited and annealed in situ immediately prior to superlattice film growth. Variations in TS between 150 and 320 °C had no effect on either the amplitude of composition modulation in deposited films or on the minimum layer thickness Λmin obtainable from a given set of sputtering conditions. Λmin was, however, found to be dependent on the sputtering pressure and was limited by ion-bombardment-enhanced diffusion during film growth. A model is discussed for determining bombardment-enhanced diffusion coefficients D* as a function of growth conditions using measured x-ray superlattice diffraction intensities. Values of D* obtained in this way were several orders of magnitude larger than thermal diffusion coefficients found from postannealing experiments.

Anisotropy of the volume plasmon dispersion of InSb

The dispersion of the volume plasmon in single-crystal InSb films has been observed, by measurements of the inelastic scattering of 56 keV electrons with momentum transfers up to q=1.0 AA-1. For momentum transfers q>0.2 AA-1 parallel to different crystal axes, different dispersion curves have been found. In addition, the dependence Delta Ep(q2) yields a change in the slope in the region 0.15 AA-2<q<0.25 AA-2. These results are compared with those of other substances.