In Situ Synchrotron X-Ray Topography Observation of Double-Ended Frank-Read Sources in PVT-Grown 4H-SiC Wafers


Article Preview

We present in-situ observations of the dynamical operation of multiple double-ended Frank-Read dislocation sources in a PVT-grown 4H-SiC wafer under thermal gradient stresses. The nucleation of these sources is facilitated by a specific configuration consisting of one basal plane dislocation (BPD) segment pinned by two threading edge dislocations (TEDs). This configuration is formed during PVT crystal growth by deflection of TEDs on to the basal planes by macrosteps and re-deflection of resulting BPDs back into TEDs. Under the influence of thermal gradient stresses induced by heating inside a double ellipsoidal mirror furnace, the pinned BPD segment glides and activates dislocation multiplication by the double Frank-Read source mechanism. A more intricate mechanism of swapping of TED pinning points between Frank-Read sources lying on same basal plane is identified, enabling one dislocation loop to effectively “pass through” the other dislocations on same basal plane.



Edited by:

Robert Stahlbush, Philip Neudeck, Anup Bhalla, Robert P. Devaty, Michael Dudley and Aivars Lelis




Y. Yang et al., "In Situ Synchrotron X-Ray Topography Observation of Double-Ended Frank-Read Sources in PVT-Grown 4H-SiC Wafers", Materials Science Forum, Vol. 924, pp. 172-175, 2018

Online since:

June 2018




* - Corresponding Author

[1] F. C. Frank and W. T. Read Jr., Phys. Rev. 79 (4) (1950) 722.

[2] W.C. Dash in: Dislocations and Mechanical Properties of Crystals, eds. J. C. Fisher, W. G. Johnston, R. Thomson and T. Vreeland Jr., Wiley, New York (1957) 75-68.

[3] S. Y. Cheung, N. J. Ho and H. Y. Lu, J. Amer. Ceram. Soc. 89 (2006) 1659–1667.

[4] H. Wang, F. Wu, S. Byrappa, S. Sun, B. Raghothamachar, M. Dudley, E. K. Sanchez, D. Hansen, R. Drachev, S. G. Mueller and M. J. Loboda, Appl. Phys. Lett. 100 (17) (2012) 172105.


[5] A. Danilewsky, J. Wittge, A. Hess, A. Cröll, D. Allen, P. McNally, P. Vagovič, A. Cecilia, Z. Li, T. Baumbach, E. Gorostegui-Colinas, M. R. Elizalde, Nucl. Instrum. Methods Phys. Res. B 268 (2010) 399–402.


Fetching data from Crossref.
This may take some time to load.