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In situ synchrotron x-ray topography observation of double-ended

DOI: 10.4028/www.scientific.net/MSF.924.172 DOI Help

Authors: Yu Yang (Stony Brook University) , Jian Qiu Guo (Universität Freiburg) , Balaji Raghothamachar (Stony Brook University) , Michael Dudley (Stony Brook University) , Swetlana Weit (Universität Freiburg) , Andreas N. Danilewsky (Universität Freiburg) , Patrick J. Mcnally (Dublin City University) , Brian K. Tanner (Durham University)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Materials Science Forum , VOL 924 , PAGES 172 - 175

State: Published (Approved)
Published: June 2018
Diamond Proposal Number(s): 13464

Abstract: 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 the same basal plane is identified, enabling one dislocation loop to effectively “pass through” the other dislocations on the same basal plane.

Journal Keywords: SiC; Double ended Frank-Read sources; slip

Subject Areas: Materials, Physics, Technique Development


Instruments: B16-Test Beamline