Download or read book Finite Element Modeling of Dislocation Multiplication in Silicon Carbide Crystals Grown by Physical Vapor Transport Method written by Qingde Chen and published by . This book was released on 2015 with total page 133 pages. Available in PDF, EPUB and Kindle. Book excerpt: Silicon carbide as a representative wide band-gap semiconductor has recently received wide attention due to its excellent physical, thermal and especially electrical properties. It becomes a promising material for electronic and optoelectronic device under high-temperature, high-power and high-frequency and intense radiation conditions. During the Silicon Carbide crystal grown by the physical vapor transport process, the temperature gradients induce thermal stresses which is a major cause of the dislocations multiplication. Although large dimension crystal with low dislocation density is required for satisfying the fast development of electronic and optoelectronic device, high dislocation densities always appear in large dimension crystal. Therefore, reducing dislocation density is one of the primary tasks of process optimization. This dissertation aims at developing a transient finite element model based on the Alexander-Haasen model for computing the dislocation densities in a crystal during its growing process. Different key growth parameters such as vi temperature gradient, crystal size will be used to investigate their influence on dislocation multiplications. The acceptable and optimal crystal diameter and temperature gradient to produce the lowest dislocation density in SiC crystal can be obtained through a thorough numerical investigation using this developed finite element model. The results reveal that the dislocation density multiplication in SiC crystal are easily affected by the crystal diameter and the temperature gradient. Generally, during the iterative calculation for SiC growth, the dislocation density multiples very rapidly in the early growth phase and then turns to a relatively slow multiplication or no multiplication at all. The results also show that larger size and higher temperature gradient causes the dislocation density enters rapid multiplication phase sooner and the final dislocation density in the crystal is higher.
Download or read book Formation and Properties of Dislocations During Crystal Growth of Bulk Silicon Carbide by the Physical Vapor Transport Method written by Sakwe Aloysius Sakwe and published by . This book was released on 2008 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Crystallographic Finite Element Modeling for Dislocation Generation in Semiconductor Crystals Grown by VGF Process written by Gary Sheu and published by . This book was released on 2006 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Kinetics of Silicon Carbide Single Crystal Growth in the Physical Vapor Transport Process written by and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 A Unique High temperature High pressure Crystal Growth System for Silicon Carbide written by J. R. Littler and published by . This book was released on 1973 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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).
Download or read book Growth and Mechanical Properties of Filamentary Silicon Carbide Crystals written by Luke A. Yerkovich and published by . This book was released on 1961 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Three dimensional Modeling of Solution Crystal Growth Via the Finite Element Method written by Bhushan Vartak and published by . This book was released on 2001 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Influence of Stoichiometry on Electrical Properties of Silicon Carbide Grown by Physical Vapor Transport Process written by Qiang Li and published by . This book was released on 2005 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Computer Simulations of Dislocations written by Vasily Bulatov and published by Oxford University Press. This book was released on 2006-11-02 with total page 301 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book presents a variety of methods for computer simulations of crystal defects in the form of "numerical recipes", complete with computer codes and analysis tools. By working through numerous case studies and problems, this book provides a useful starter kit for further method development in the computational materials sciences.
Download or read book Sublimation Growth and Performance of Cubic Silicon Carbide written by and published by . This book was released on 2012 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this work was to develop operation conditions for fabrication of 3C-SiC crystals via understanding fundamentals of the growth process and to explore structural and electrical properties of the grown material, including its suitability for substrate applications. The physical vapor transport or sublimation process has already shown a capability to produce substantial quantities of large area and high quality hexagonal SiC substrates. In the present study a similar growth principle, but in a different geometry, namely sublimation epitaxy, was applied. Using this method very high growth rates (up to 1 mm/h) can be achieved for hexagonal polytypes while maintaining high material quality. Additionally, the growth process does not require expensive or hazardous materials, thus making the method very attractive for industrial use.
Download or read book Growth Phenomena in Silicon Carbide written by Wilhelmus Franciscus Knippenberg and published by . This book was released on 1963 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Integrated Intelligent Modeling Design and Control of Crystal Growth Processes written by and published by . This book was released on 2000 with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt: Growth of single crystals is the critical beginning step for electronic, opto-electronic, MEMS and many other devices. This MURI program took an integrated approach towards modeling, design and control of crystal growth processes and in conjunction with growth and characterization experiments developed much better understanding of growth phenomena and materials defects. It led to the development of most comprehensive and accurate models that account for conduction, convection and volumetric, spectral radiation heat transfer, oscillatory and turbulent flows, transport and segregation of dopants and impurities, phase change, an applied magnetic and/or electric field, and generation and multiplication of crystal defects. Using state-of-the-art adaptive grid generation techniques and parallel algorithms, the models can perform three-dimensional, dynamic simulations. While establishing white beam x-ray topography as the leading technique for crystal characterization, this research led to many new theories for grow the behavior and defects. Advanced model-based control algorithms were developed for in-situ synthesis and Czochralski growth. Notable among many successful technology transfer projects are: AFRL-developed one-step in-situ synthesis and growth of indium phosphide crystals, growth of large diameter silicon carbide crystals, 500 mm diameter silicon tube growth, transport model for hydrothermal growth, wire saw technology and high yield polysilicon production. Besides involving numerous faculty, the project succeeded in training a large number of postdoctoral fellows and undergraduate and graduate students in crystal growth.
Download or read book Electrical Electronics Abstracts written by and published by . This book was released on 1997 with total page 2304 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Silicon Carbide written by I. N. Frantsevich and published by Springer. This book was released on 1970 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling of the Sublimation Growth of Silicon Carbide Crystals written by Peter Råback and published by . This book was released on 1999 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt:
