Direct observation of basal-plane to threading-edge dislocation conversion in 4H-SiC epitaxy
Abstract
The propagation behavior of basal plane dislocations from off-oriented 4H-SiC substrates into homoepitaxial layers has been investigated using transmission electron microscopy (TEM), secondary electron microscopy (SEM), and chemical etching. Cross-sectional TEM shows that basal plane dislocations in the substrate are dissociated into pairs of partial dislocations separated by a stacking fault with a width of about 40 nm. Near the substrate/epilayer interface, where most of the basal plane dislocations convert to threading edge dislocations, the two partials constrict before converting. Threading edge segments are inclined by about 20° from the c-axis toward the down-step direction. It is concluded that the critical and limiting step of the dislocation conversion process is constriction of the dissociated partials. Growth surface morphology at the emergence point of the basal plane dislocation was imaged using SEM and is thought to play an important role in the constriction.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- May 01, 2011
- Source ID
- 10.1063/1.3579447
Entities
People
- Charles. R. Eddy Jr.
- D. Kurt Gaskill
- Marek Skowronski
- Ping Wu
- Rachael Myers-ward
- Suk Chung
- Virginia D. Wheeler
- Yoosuf N. Picard
Organizations
- Carnegie Mellon University
- II-VI Incorporated
- Office of Naval Research
- United States Naval Research Laboratory