**Author details**

T. S. Argunova1,2, M. Yu. Gutkin3,4,5, J. H. Je2,, V. G. Kohn<sup>6</sup> and E. N. Mokhov<sup>1</sup>

1Ioffe Physical-Technical Institute, RAS, St. Petersburg, Russia

2X-ray Imaging Center, Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang, Republic of Korea

3Institute of Problems in Mechanical Engineering, RAS, St. Petersburg, Russia

4Department of Physics of Materials Strength and Plasticity, St. Petersburg State Polytechnical University, St. Petersburg, Russia

5Department of Theory of Elasticity, St. Petersburg State University, St. Petersburg, Russia 6Russian Research Center 'Kurchatov Institute', Moscow, Russia

### **References**

16 Physics and Technology of Silicon Carbide Devices

The evolution of defects was investigated by using on-axis and axial-cut slices prepared from 6*H* and 4*H*-SiC PVT grown crystals. SR phase contrast imaging enabled us to visualize not only MPs and the pores formed at the boundaries of FPIs, but also their changes during SiC growth. Detailed mechanisms for the evolution from FPIs to pores and finally to MPs were suggested. In the early growth stage, FPIs not only induce massive generation of full-core dislocations and MPs but also attract them, forming slit-type pores at the boundaries of FPIs. In the intermediate stage, when FPIs stop to grow and become overgrown by the matrix, the pore density significantly reduces, which is attributed to their transformation into new MPs. In the later stage, the MP density decreases, providing evidence for their partial annihilation

The reactions of MPs in view of their elimination during the crystal growth were briefly reviewed. The reduction of MP cross-section, which can eventually results in its overgrowth, occurs at the crystal growth when MP splits, as well as merges or interacts with another MP in a non-contact mode. The split happens if the splitting dislocation overcomes the MP attraction zone and the flat crystal surface attraction zone. Merging can occur due to collective mesoscopic effects in a random ensemble of MPs. The twisted dipoles result under the action of neighboring MPs. When the magnitudes of Burgers vectors are the same, the dipole is transformed into a new configuration of a semiloop. Such reactions of ramification and coalescence of MPs, as well as annihilation for dipoles of MPs, were observed by phase-contrast imaging. Computer simulation of phase-contrast images demonstrated the correlated reduction in the radii of two remote MPs, which provided a support of contact-free

This study suggests that the key point for the elimination of defects from such crystals is the suppression of FPI nucleation. The reactions of MPs are necessary for diminishing their

This work was supported by the Creative Research Initiatives (Functional X-ray Imaging) of MEST/KOSEF of Korea. The work of VGK was supported by RFBR grant No. 1002-00047-a.

2X-ray Imaging Center, Department of Materials Science and Engineering, Pohang University

4Department of Physics of Materials Strength and Plasticity, St. Petersburg State

5Department of Theory of Elasticity, St. Petersburg State University, St. Petersburg, Russia

3Institute of Problems in Mechanical Engineering, RAS, St. Petersburg, Russia

density; and such reactions should be faster as the surface energy becomes smaller.

**6. Conclusions**

and healing.

reaction between them.

**Acknowledgements**

**Author details**

T. S. Argunova1,2, M. Yu. Gutkin3,4,5, J. H. Je2,, V. G. Kohn<sup>6</sup> and E. N. Mokhov<sup>1</sup>

1Ioffe Physical-Technical Institute, RAS, St. Petersburg, Russia

6Russian Research Center 'Kurchatov Institute', Moscow, Russia

of Science and Technology, Pohang, Republic of Korea

Polytechnical University, St. Petersburg, Russia


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Chapter 3

Ion Synthesis of SiC and Its Instability at High

/z %/z '\*+3\*\_z /1\$z 2\*0#!/z +"z /%(%+\*z .% !z /z z \$%#\$z \$. \*!//z cG0\$z ,(!z "0!.z %¥ mond) [36, 37], high chemical and radiation resistance, high melting point, etc. became the basis of its wide application not only in microelectronics [1f\_z10z(/+z/z.!".0+.5z\* z.¥ sive materials. Silicon carbide is included in the oxidation resistant composite materials [42] used in coating system for "Space Shuttle", capable of withstanding temperatures up to DHCC[z0z0\$!z!\*0.\*!z+"z0\$!z/\$%,z%\*0+z0\$!z0)+/,\$!.!^z \*z)\*5z00!),0/z0+z !2!(+,z\*z!"¥ fective oxidation-protection coating for carbon-carbon composites with excellent mechanical properties at elevated temperature, silicon carbide coating has shown the best performance for short periods of up to 1900K [39f^z +.z(+\*#!.z,!.%+ /z \* z \$%#\$!.z 0!),!.01.!z ,,(%¥

Silicon carbide is regarded by researchers as a suitable material for the front wall structures of fusion reactors. The boers, cutting disks, grinding paper of SiC can be used for boring, drilling, surface grinding and cutting of steel, nonferrous metals, natural stone, concrete,

\$!z/0%(%05z+"z/%(%+\*z.% !z0+z\$%#\$z0!),!.01.!z0.!0)!\*0z%/z+"z/,!%(z%\*0!.!/0^z/zz/,!¥ cial application, silicon carbide can be thermally oxidized in the form of SiO2\_z\* z0\$!z !2%¥ ces which can be easily fabricated on Si substrate (Power MOSFET, IGBT, MOS controlled thyristor, etc.) can also be fabricated on SiC substrate [23]. In paper [23] the parabolic growth of thickness of thermal oxide versus oxidation time was observed, and the slope of the plots increases with increasing temperature. The thickness values of oxide films were about 23-77 \*)zc%w"!\_z3!0z+4% 0%+\*d\_zDKwIFz\*)zc%w"!\_z .5z+4% 0%+\*d\_zEDCwKDCz\*)zcw"!\_z3!0z+4% ¥ 0%+\*dz\* zDEHwEICz\*)zcw"!\_z .5z+4% 0%+\*dz"+.z+4% 0%+\*z0%)!zIz\$z\* z !,!\* z+\*z0!),!.¥

> © 2013 Nussupov and Beisenkhanov; licensee InTech. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is

distribution, and reproduction in any medium, provided the original work is properly cited.

© 2013 Nussupov and Beisenkhanov; licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use,

Kair Kh. Nussupov and Nurzhan B. Beisenkhanov

Additional information is available at the end of the chapter

tions, a challenging coating system should be developed.

Temperatures

http://dx.doi.org/10.5772/ 51389

1. Introduction

wood and plastic.

ture value (1000, 1050, 1110 or 1150°C).

properly cited.
