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The Simulation of Bragg-Case Section Images οf Dislocations and Inclusions in Aspect of Identification of Defects in SiC Crystals

100%

Balcer T., Wierzchowski W., Wieteska K.

Acta Physica Polonica A

2010

vol. 117

issue 2

336-340

The numerical simulation has been applied for studying of Bragg-case section topographic images of dislocation and rod-like inclusions. The validity of simple approximation of extinction contrast was confirmed in the case of screw dislocations in silicon carbide crystals. A procedure for approximate calculation of the strain field of rod-like inclusion was constructed, consisting of adding the contributions from a very large number of point-like inclusions uniformly distributed inside the assumed volume of the inclusion. The procedure ensured a reasonable similarity between the simulated topographs and experimental Bragg-case section topographic images of some pipe-formed cavities in silicon carbide crystals. The method is useful for some other materials, e.g. it enabled to compute realistic simulation of plane-wave topographs of the rod-like inclusions in YAG.

Topographic and Reflectometric Investigation of Crystallographic Defects and Surface Roughness in 4H Silicon Carbide Homoepitaxial Layers Deposited at Various Growth Rates

76%

Wierzchowski W., Wieteska K., Mazur K., Kościewicz K., Balcer T., Strupiński W., Paulmann C.

Acta Physica Polonica A

2012

vol. 121

issue 4

915-919

Undoped 4H silicon carbide epitaxial layers were deposited by means of CVD method with growth rates of 2 μm/h, 5 μm/h and 11 μm/h at 1540°C on n-doped 8°, 4° and 0° off-cut 4H-SiC (00·1) substrates. The structural defects were studied before and after growth of the epitaxial layers by means of conventional Lang topography, synchrotron white beam and monochromatic beam topography and by means of X-ray specular reflectometry. The topographic investigations confirmed the continuation of the dislocations in the epitaxial deposit on the 8° and 4° off-cut substrates without new extended defects. The important difference occurred in the surface roughness of the epitaxial layers, which increased for higher growth rates. The epitaxial layers grown on 0° off-cut substrates at analogous condition contained usually other SiC polytypes, but the influence of the growth rate on the distribution of the polytypes was observed.

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2 Acta Physica Polonica A

1 2012

1 2010

2 Balcer T.

2 Wierzchowski W.

2 Wieteska K.

1 Kościewicz K.

1 Mazur K.

1 Paulmann C.

1 Strupiński W.

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The Simulation of Bragg-Case Section Images οf Dislocations and Inclusions in Aspect of Identification of Defects in SiC Crystals

Topographic and Reflectometric Investigation of Crystallographic Defects and Surface Roughness in 4H Silicon Carbide Homoepitaxial Layers Deposited at Various Growth Rates