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Sun W.,CAS Institute of Physics | Song Y.,CAS Institute of Physics | Liu C.,CAS Institute of Physics | Peng T.,Beijing Tankeblue Semiconductor Co. | And 2 more authors.
Materials Express | Year: 2015

Threading edge dislocations (TEDs), threading screw dislocations (TSDs), basal plane dislocations (BPDs) are common line dislocations occurring in silicon carbide crystals. Complex dislocations are a combination of two Delivered by Publishing Technology to: Elsevier BV types or more of individual dislocations and have been less studied. Here, we report the characterization and the formation mechanism of a com Coppleyxrigdhist:lo Acmateiornicacno nSsci isetnintgifico Pf uobnleishBePrsD and two TEDs in 6H-SiC single crystals. Our experimental results show that this type of complex dislocations can occur frequently in single crystals as in epitaxial films. We reveal that it originates from an interaction of a TED and a BPD. This interaction is likely to induce the emergence of a new TED. © 2015 by American Scientific Publishers. All rights reserved. Source

Wang B.,CAS Institute of Physics | Peng T.,Beijing Tankeblue Semiconductor Co. | Liang J.,CAS Institute of Physics | Wang G.,CAS Institute of Physics | And 3 more authors.
Applied Physics A: Materials Science and Processing | Year: 2014

Here, we report a commonly occurring defect related to nitrogen doping in silicon carbide crystals grown by physical vapor transport method while its formation mechanism has remained unclear. It is often mislabeled as planar hexagonal void defect (PHVD) owing to their similar in shape and size on wafer surface. Our results indicate that this is a new type of defect and differs from PHVD with respect to their nitrogen concentrations, void shapes and the connections to micropipe. We found that the carbon-rich vapor during the crystal growth is responsible for the formation of this type of defect. A possible three-stage defect developing mechanism and measures to avoid the defects are proposed. © 2014, Springer-Verlag Berlin Heidelberg. Source

Liu C.,CAS Institute of Physics | Chen X.,CAS Institute of Physics | Peng T.,Beijing Tankeblue Semiconductor Co. | Wang B.,CAS Institute of Physics | And 2 more authors.
Journal of Crystal Growth | Year: 2014

4H-SiC crystals containing polytype defects are investigated by optical microscopy, atomic force microscopy, and Raman scattering, aiming at understanding the mechanism of polytype transformation during growth processes. It is observed that the crystal surfaces around the facet are uneven and contain many macroscopic triangular domains, consisting of wide triangular terraces and giant macrosteps. Nucleation and growth on the wide terraces are demonstrated to be responsible for the polytype transformation. A possible polytype transformation mechanism is put forward, which can explain the stabilizing effect of nitrogen on 4H-SiC growth. © 2014 Elsevier B.V. Source

Zuo S.,CAS Institute of Physics | Wang J.,CAS Institute of Physics | Chen X.,CAS Institute of Physics | Jin S.,CAS Institute of Physics | And 5 more authors.
Crystal Research and Technology | Year: 2012

6H-SiC (0001) deposited 300 nm thick AlN film by MOCVD was used as the substrate to grow AlN crystals by the physical vapour transport (PVT) method. It was confirmed that c-axis oriented AlN films were grown and this material had a 3D growth mode. The root mean square (RMS) value for the film was measured to be 2.17 nm. Nucleation and further growth of AlN on so prepared substrate was investigated. Colorless and transparent AlN crystal with 1 mm thick and 40 mm in diameter was obtained after 4 h growth on this substrate. The transparent AlN showed strong (0001) texture XRD patterns, only the (0002) reflection was observed in symmetric Î-2Î scans. The full width at half maximum for a (0002) X-ray rocking curve was less than 0.1° indicating good crystalline quality. Anisotropic etchings in molten KOH shows that the growth (0001) plane exposed to the AlN source predominately has an aluminum polarity, no N-polar inversion domains were observed. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Wang W.J.,CAS Institute of Physics | Zuo S.B.,CAS Institute of Physics | Bao H.Q.,Beijing Tankeblue Semiconductor Co. | Wang J.,CAS Institute of Physics | And 2 more authors.
Crystal Research and Technology | Year: 2011

The growth of AlN crystals by PVT method was investigated using TaC crucible in the temperature range of 2250-2350 °C. AlN boules with 30 mm in diameter were successfully grown on the crucible lid by self-seeded growth. The AlN boules consist of the spontaneously nucleated AlN single crystal grains with the {1010} natural crystalline face. The fast growth rate of more than 1 mm/h was achieved. AlN crystals grown on (11̄20)-, (10̄10)-, and (0001)-face AlN seeds were investigated. Different experimental phenomena have been observed under particular condition. The crystal grown on (11̄20)-face seed has different natural crystalline face from the seed. For the crystal grown on (10̄10) or (0001) seed, the crystal natural crystalline face is same as the crystallographic orientation of the seed. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

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