A Unique High Temperature High Pressure Crystal Growth System For Silicon Carbide

A high-pressure, high-temperature furnace system is described for crystal growth experiments using crucibles up to 13 cm in diameter and 26 cm high. The vertical temperature gradient is electronically controlled during growth such that the ends of the crucible can be maintained at temperatures above or below the crucible center. Temperatures up to 2800C can be maintained at pressures up to 50 atmospheres. A vacuum capability up to .000001 torr at 1800C has been incorporated into the system. Single crystals of alpha silicon carbide grown in this system at 2600C are described to illustrate its use. (Author).

A high-pressure, high-temperature furnace system is described for crystal growth experiments using crucibles up to 13 cm in diameter and 26 cm high. The vertical temperature gradient is electronically controlled during growth such that the ends of the crucible can be maintained at temperatures above or below the crucible center. Temperatures up to 2800C can be maintained at pressures up to 50 atmospheres. A vacuum capability up to .000001 torr at 1800C has been incorporated into the system. Single crystals of alpha silicon carbide grown in this system at 2600C are described to illustrate its use. (Author).

Crystals are the unacknowledged pillars of modern technology. The modern technological developments depend greatly on the availability of suitable single crystals, whether it is for lasers, semiconductors, magnetic devices, optical devices, superconductors, telecommunication, etc. In spite of great technological advancements in the recent years, we are still in the early stage with respect to the growth of several important crystals such as diamond, silicon carbide, PZT, gallium nitride, and so on. Unless the science of growing these crystals is understood precisely, it is impossible to grow them as large single crystals to be applied in modern industry. This book deals with almost all the modern crystal growth techniques that have been adopted, including appropriate case studies. Since there has been no other book published to cover the subject after the Handbook of Crystal Growth, Eds. DTJ Hurle, published during 1993-1995, this book will fill the existing gap for its readers.The book begins with ""Growth Histories of Mineral Crystals"" by the most senior expert in this field, Professor Ichiro Sunagawa. The next chapter reviews recent developments in the theory of crystal growth, which is equally important before moving on to actual techniques. After the first two fundamental chapters, the book covers other topics like the recent progress in quartz growth, diamond growth, silicon carbide single crystals, PZT crystals, nonlinear optical crystals, solid state laser crystals, gemstones, high melting oxides like lithium niobates, hydroxyapatite, GaAs by molecular beam epitaxy, superconducting crystals, morphology control, and more. For the first time, the crystal growth modeling has been discussed in detail with reference to PZT and SiC crystals.

The report describes the design, installation, calibration, and test of a unique high pressure, high temperature crystal growth system of the Solid State Sciences Laboratory of Air Force Cambridge Research Laboratories. A number of modifications and innovations that make the system unique are described. Pictures and diagrams of the crystal growth system are sufficiently complete to provide substantial aid in the operation or duplication of this facility. This furnace has been operated above 3000C at internal pressures of twenty atmospheres and at a vacuum in the low 0.00001 Torr range. (Author).

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.

This volume deals with the technologies of crystal fabrication, of crystal machining, and of epilayer production and is the first book on industrial and scientific aspects of crystal and layer production. The major industrial crystals are treated: Si, GaAs, GaP, InP, CdTe, sapphire, oxide and halide scintillator crystals, crystals for optical, piezoelectric and microwave applications and more. Contains 29 contributions from leading crystal technologists covering the following topics: * General aspects of crystal growth technology * Silicon * Compound semiconductors * Oxides and halides * Crystal machining * Epitaxy and layer deposition Scientific and technological problems of production and machining of industrial crystals are discussed by top experts, most of them from the major growth industries and crystal growth centers. In addition, it will be useful for the users of crystals, for teachers and graduate students in materials sciences, in electronic and other functional materials, chemical and metallurgical engineering, micro-and optoelectronics including nanotechnology, mechanical engineering and precision-machining, microtechnology, and in solid-state sciences.

The report describes the design, installation, calibration, and test of a unique high pressure, high temperature crystal growth system of the Solid State Sciences Laboratory of Air Force Cambridge Research Laboratories. A number of modifications and innovations that make the system unique are described. Pictures and diagrams of the crystal growth system are sufficiently complete to provide substantial aid in the operation or duplication of this facility. This furnace has been operated above 3000C at internal pressures of twenty atmospheres and at a vacuum in the low 0.00001 Torr range. (Author).

Volumes 11 and 12 contain the papers read at the Fourth All-Union Conference on Crystal Growth in Tsakhkadzor, September 17-22, 1972; this volume contains papers on crystal growth from melts, from low-temperature solutions, hydrothermal solutions, and hot solutions, and also from the gas state, including processes involving reactions. In addition, there are papers on crystal perfection in relation to conditions of formation and the effects of electric and mag netic fields on crystallization. These papers reflect researches directed to the development and industrial production of perfect crystals required for advanced techniques in solid-state physics and chemistry, as well as for other purposes such as novel materials. There are many different scientific and technical problems in producing large perfect single crystals, and advances in this area made in the USSR and elsewhere are reflected in the papers in both volumes. On the one hand, any particular defective structure in a crystal originates from some mechanism and growth conditions; in particular, inclusions are trapped on account of the physicochemical parameters of the melt, the surface processes, and the sta bility of the growth front under particular crystallization conditions. Further, impurity trap ping is decisively influenced by the surface kinetics, growth-front stability, composition and structure of the boundary layer, any complexes present in the liquid, and (of course) the crys tallochemical relationships between the impurity and the crystal.

A valuable, timely book for the crystal growth community, edited by one of the most respected members in the field. Contents cover all the important materials from silicon through the III-V and II-IV compounds to oxides, nitrides, fluorides, carbides and diamonds International group of contributors from academia and industry provide a balanced treatment Includes global interest with particular relevance to: USA, Canada, UK, France, Germany, Netherlands, Belgium, Italy, Spain, Switzerland, Japan, Korea, Taiwan, China, Australia and South Africa

Single crystals of over 100 different electronically active materials have been synthesized using a variety of methods, including growth by flame-fusion, flux, melt, gel diffusion, low-temperature solution, vapor, as well as synthesis by ultra-high-pressure techniques. These crystals, including a large number of doped specimens, emphasize oxides, garnets, silicates, ferrites, fluorides, as well as a large variety of other electromagnetic materials. Charts are presented giving summary data on single crystals grown, percentage and kind of dopants, growth methods and apparatus, crystal dimensions and other physical characteristics, primary research interest or use, crystal system, class, space group, and pertinent references. Several of the growth methods and recent Laboratory accomplishments are described. (Author).