Download or read book Relation Between Growth Temperature and the Structure of SiC Crystals Grown by the Sublimation Method written by Yoshizō Inomata and published by . This book was released on 1969 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: The relationship between growth temperature and the polytypes of SiC crystals has been studied experimentally at 2200 degrees C to 2600 degrees C under conditions of low supersaturation. The results are summarized as follows: (1) In the present experiment, excluding one example in which the 4 H-type was involved, the structure of all crystals consisted of the 6 H-, 15 R- and other long c-period types exceeding 21. Of the elemental structures of SiC, 2 H, 3 C, 4 H, 15 R, 6 H, and 21 R, only 6 H and 15 R were found. (2) In the range of 2200 degrees C - 2600 degrees C, 6 H and 15 R have the most thermal stability among the structures considered as elemental. However, the effect of impurity in the crystal and the shift from stoichiometry were neglected. (3) The relative amount of 15 R increased with decreasing temperature while 6 H showed the opposite tendency.
Download or read book On the Formation of Beta SiC in the Initial Growth Stage written by Yoshizō Inomata and published by . This book was released on 1972 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: The formation of Beta-SiC at temperatures outside its thermally stable range of 1,400-1,600C was studied experimentally using the sublimation procedure and the synthetic method with molten silicon. From consideration of the molar surface energy of Beta- and alpha-SiC, the following are shown to be the main causes for the phenomenon: (1) Given an equal volume of crystallites, the molar surface energy of the Beta-type is always lower than that of the alpha-type based on its higher lattice symmetry; (2) the bonding energy of the Beta-type is the lowest among the SiC polytypes from comparison of the band gaps; (3) the rate of transition from the Beta- to the alpha-type is not too large. The free energy gaps among the SiC polytypes were found to be smaller than 100 cal/mole. The effects of pressure and polarity are also discussed.
Download or read book Carbon Particle Inclusions in SiC Single Crystals Prepared by Sublimation written by Yoshizō Inomata and published by . This book was released on 1971 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: Several experiments were performed to clarify the process of carbon particle inclusion in crystals grown by Lely's sublimation procedure. Special attention was paid to the effect of the cavity wall, recrystallization temperature, and the increasing heating rate. It was found, using the technique of dark field photomicrography, that the density of the inclusions in the crystals often showed certain orientation and zonal structure. These features are explained by the microscopic temperature distribution and temperature fluctuation in a crystal. From the relation between the observed results and growth conditions, it was concluded that the phenomenon is attributed primarily to the shifting of the vapor phase composition in the growth cavity to the carbon side from the equilibrium condition.
Download or read book Effect of Growth Rate on the Structure and Stacking Disorder of SiC Crystals Grown by the Lely Method written by Yoshizō Inomata and published by . This book was released on 1969 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: The relation between the structure of SiC and its growth rate was studied at 2500 degrees C. The setting of the growth condition was improved by limiting the zone of recrystallization in the growth cavity. Super-saturation in the cavity was changed in several steps by the use of the cavity wall and thermo-insulator.
Download or read book The Growth of SiC Crystals from Vapor by the Bridgman Stockbarger Method written by Juris Smiltens and published by . This book was released on 1974 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: From the dissociation curve (P vs. T), an equation for the rate of raising the pressure P of the binary vapor for obtaining the required linear growth rate of the crystal of c centimeters per hour is derived. It is shown that the rate is nearly proportional to P. Modifications of the furnace since the last report (Mat. Res. Bull. 4, S85, 1969) are described. Justification for the use of helium as the inert ambient gas is given. Two techniques are used: (1) growing with constant temperature of the crucible point and (2) growing with constant pressure of the sublimation bottle. To date, only polycrystalline boules consisting of large grains have been obtained. It is believed, however, that with certain technological improvements the methods that are developed here will ultimately yield single crystal boules. As a by-product, small cubic crystals, about one mm in the largest dimension, with good quality faces (cube and octahedron) have been obtained.
Download or read book NBS Special Publication written by and published by . This book was released on 1918 with total page 1164 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1971 with total page 1330 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Crystal Growth written by Vadim Glebovsky and published by BoD – Books on Demand. This book was released on 2019-11-06 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book, a variety of topics related to crystal growth is extensively discussed. The topics encompass the physics of growing single crystals of different functional materials, single-crystalline thin films, and even the features of crystallization of biofats and oils. It is intended to provide information on advancements in technologies for crystal growth to physicists, researches, as well as engineers working with single-crystalline functional materials.
Download or read book U S Government Research Development Reports written by and published by . This book was released on 1970 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Silicon Carbide and Related Materials 2007 written by Akira Suzuki and published by Trans Tech Publications Ltd. This book was released on 2008-09-26 with total page 1434 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wide-bandgap semiconductors, such as silicon carbide and group-III nitrides have attracted increasing attention as promising target materials for high-power, high-frequency and high-temperature electronics use, as well as exploitation as short-wavelength light-emitters. Volume is indexed by Thomson Reuters CPCI-S (WoS).
Download or read book Growth of 2H Silicon Carbide Crystals written by J. Anthony Powell and published by . This book was released on 1969 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Growth of Crystals written by E. Givargizov and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present volume continues the tradition of the preceding volumes. covering a wide range of crystal growth problems and treating aspects of critical importance for crystalliza tion. Changes in this field of knowledge have. however, changed the criteria for selection of papers for inclusion in this series. The increasing role of crystals in science and technology is even more apparent today. The study and utilization of these highly perfect objects of nature considerably facilitates progress in the physics and chemistry of solids. quantum electronics, optics, microelectron ics, and other sciences. The demand for crystals and crystal devices has grown steadily and has led to the emergence and rapid growth of the single crystal industry (we can safely saythat the state ofthe art in this industry is indicative ofthe overall scientific and technolo- cal potential of a country). At the same time, the introduction of crystallization techniques into other industries is gaining ever-increasing importance. To illustrate this last state ment, we can mention the fabrication of textured structural materials and direct methods of metal reduction in ores by using chemical vapor transport techniques. Crystallization tech ll niques progress both in "width" and in "depth : traditional methods are modernized. and novel techniques appear, some of them at the junction of the already existing technologies (for example, flux growth of crystals, growth from vapor with participation of the liquid phase, etc. ).
Download or read book Consolidated Translation Survey written by and published by . This book was released on 1969-05 with total page 738 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book CVD growth of SiC for high power and high frequency applications written by Robin Karhu and published by Linköping University Electronic Press. This book was released on 2019-02-14 with total page 55 pages. Available in PDF, EPUB and Kindle. Book excerpt: Silicon Carbide (SiC) is a wide bandgap semiconductor that has attracted a lot of interest for electronic applications due to its high thermal conductivity, high saturation electron drift velocity and high critical electric field strength. In recent years commercial SiC devices have started to make their way into high and medium voltage applications. Despite the advancements in SiC growth over the years, several issues remain. One of these issues is that the bulk grown SiC wafers are not suitable for electronic applications due to the high background doping and high density of basal plane dislocations (BPD). Due to these problems SiC for electronic devices must be grown by homoepitaxy. The epitaxial growth is performed in chemical vapor deposition (CVD) reactors. In this work, growth has been performed in a horizontal hot-wall CVD (HWCVD) reactor. In these reactors it is possible to produce high-quality SiC epitaxial layers within a wide range of doping, both n- and p-type. SiC is a well-known example of polytypism, where the different polytypes exist as different stacking sequences of the Si-C bilayers. Polytypism makes polytype stability a problem during growth of SiC. To maintain polytype stability during homoepitaxy of the hexagonal polytypes the substrates are usually cut so that the angle between the surface normal and the c-axis is a few degrees, typically 4 or 8°. The off-cut creates a high density of micro-steps at the surface. These steps allow for the replication of the substrates polytype into the growing epitaxial layer, the growth will take place in a step-flow manner. However, there are some drawbacks with step-flow growth. One is that BPDs can replicate from the substrate into the epitaxial layer. Another problem is that 4H-SiC is often used as a substrate for growth of GaN epitaxial layers. The epitaxial growth of GaN has been developed on on-axis substrates (surface normal coincides with c-axis), so epitaxial 4H-SiC layers grown on off-axis substrates cannot be used as substrates for GaN epitaxial growth. In efforts to solve the problems with off-axis homoepitaxy of 4H-SiC, on-axis homoepitaxy has been developed. In this work, further development of wafer-scale on-axis homoepitaxy has been made. This development has been made on a Si-face of 4H-SiC substrates. The advances include highly resistive epilayers grown on on-axis substrates. In this thesis the ability to control the surface morphology of epitaxial layers grown on on-axis homoepitaxy is demonstrated. This work also includes growth of isotopically enriched 4H-SiC on on-axis substrates, this has been done to increase the thermal conductivity of the grown epitaxial layers. In (paper 1) on-axis homoepitaxy of 4H-SiC has been developed on 100 mm diameter substrates. This paper also contains comparisons between different precursors. In (paper 2) we have further developed on-axis homoepitaxy on 100 mm diameter wafers, by doping the epitaxial layers with vanadium. The vanadium doping of the epitaxial layers makes the layers highly resistive and thus suitable to use as a substrate for III-nitride growth. In (paper 3) we developed a method to control the surface morphology and reduce the as-grown surface roughness in samples grown on on-axis substrates. In (paper 4) we have increased the thermal conductivity of 4H-SiC epitaxial layers by growing the layers using isotopically enriched precursors. In (paper 5) we have investigated the role chlorine have in homoepitaxial growth of 4H-SiC. In (paper 6) we have investigated the charge carrier lifetime in as-grown samples and traced variations in lifetime to structural defects in the substrate. In (paper 7) we have investigated the formation mechanism of a morphological defect in homoepitaxial grown 4H-SiC.
Download or read book Vapour Growth and Epitaxy written by G.W. Cullen and published by Elsevier. This book was released on 2013-09-03 with total page 409 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vapor Growth and Epitaxy covers the proceedings of the Third International Conference on Vapor Growth and Epitaxy, held in Amsterdam, The Netherlands on August 18-21, 1975. This conference highlights the crystal growth aspects of the preparation, characterization, and perfection of thin films of electronic interest. This book is organized into two sections encompassing 54 chapters. The first section considers the fundamental and applied crystal growth studies of silicon, III-V and II-VI compounds, and magnetic garnets. This section also describes the structure of autoepitaxial diamond films and the morphology of single crystals grown from the vapor phase. The second section deals with nucleation and crystal growth kinetic studies of whiskers and the fabrication of solar cells. This section further surveys the equilibrium, kinetics, and epitaxy in the chemical vapor deposition of silicon compounds.
Download or read book Si Silicon written by and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 562 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume concludes the coverage of silicon carbide, SiC, begun in "Silicon" Supplement Volume B 2, 1984, subtitled "Silicon Carbide - Part I". Part I described the physical properties of SiC, SiC diodes, molecular species in the SiC-C gas phase, and amorphous silicon-carbon alloys. The current Part II ("Silicon" Supplement Volume B 3,1986) covers in its initial chapter the Si-C phase diagram and in the final chapters the higher order systems of Si and C with additional elements through boron, arranged according to the Gmelin system. In between some 95% of the volume focusses on SiC, beginning with its natural occurrence, preparation and formation, and purification, continuing with its chemical analysis, manufacture of special ized forms, electrochemistry, and chemical reactions, and concluding with descriptions of its myriad applications. The final applications section covering electronic devices also describes similar applications of the amorphous Si-C alloys. The successive chapters in this volume are often closely interrelated, since it is often necessary to synthesize SiC directly in a form in which it will be applied. SiC cannot be melted and cast, nor rolled nor drawn, nor is it easily electroplated or sintered or purified. Silicon carbide first became known to man when E. G. Acheson in 1891 used an electric current to heat a mixture of clay and carbon to extremely high temperatures.
Download or read book Bibliography with Abstracts of AFCRL Publications from 1 July to 30 September 1971 written by Air Force Cambridge Research Laboratories (U.S.) and published by . This book was released on 1971 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: This bibliography lists all AFCRL in-house reports, journal articles, and contractor reports issued from 1 July to 30 September 1971. Abstracts are included.
