Synchrotron topography studies of the operation of double-ended Frank–Read partial dislocation sources in 4H-SiC

Autor: Gary E. Ruland, Balaji Raghothamachar, Michael Dudley, Fangzhen Wu, A. Souzis, Ping Wu, Ilya Zwieback, S. Byrappa, Thomas Anderson, Huanhuan Wang
Rok vydání: 2014
Předmět:
Zdroj: Journal of Crystal Growth. 401:423-430
ISSN: 0022-0248
Popis: Synchrotron White Beam X-ray Topography (SWBXT) has been used to image and analyze a distinctive stacking fault pattern observed in 4H-SiC wafers. The pattern often consists of a six-pointed star comprised of multiple layers of rhombus-shaped stacking faults with three different fault vectors of the Shockley type bounded by 30° Shockley partial dislocations. Formation of this stacking fault pattern is associated with a micropipe at its center which can act as nucleation sites for dislocation half-loops belonging to the primary basal (1/3〈11−20〉(0001)) slip system and occasionally the secondary prismatic (1/3〈11−20〉{1−100}) slip systems. In this case, the rhombus-shaped Shockley type stacking faults are nucleated on the basal plane by dissociation of 1/3〈11−20〉 pure screw dislocations cross-slipped from the prismatic plane and subsequent expansion caused by glide of the leading partial and locking of the trailing partial by interaction with 60° 1/3〈−2110〉 dislocations on the basal plane. Based on these observations, a formation mechanism involving the operation of a double-ended Frank–Read partial dislocation source has been proposed. In the limit, this glide and cross-slip mechanism leads to 4H to 3C polytype transformation in the vicinity of the micropipe by a mechanism similar to that proposed by Pirouz and Yang (1993) [21] .
Databáze: OpenAIRE
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