Nucleation of 3C-SiC associated with threading edge dislocations during chemical vapor deposition

• Published in: Journal of crystal growth Vol. 347; no. 1; pp. 45 - 48
• Main Authors: Abadier, M., Berechman, R.A., Neudeck, P.G., Trunek, A.J., Skowronski, M.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.05.2012; Elsevier
• Subjects: A1. Terrace nucleation; A1. Threading edge dislocation; A3. Heteroepitaxy; B2. 3C-Silicon Carbide; Burgers vector; Chemical vapor deposition (including plasma-enhanced cvd, mocvd, etc.); Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Defects and impurities: doping, implantation, distribution, concentration, etc; Edge dislocations; Etching; Exact sciences and technology; Materials science; Mesas; Methods of deposition of films and coatings; film growth and epitaxy; Nucleation; Physics; Strain; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Threading dislocations; A3. Heteroepitaxy; A1. Terrace nucleation; B2. 3C-Silicon Carbide; A1. Threading edge dislocation; Atomic force microscopy; Nucleation; Etching; Burgers vector; CVD; Silicon carbide; Edge dislocations; Transmission electron microscopy; Threading dislocation; Heteroepitaxy; Silicon; Bilayers
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2012.03.014

Transmission electron microscopy and atomic force microscopy were used to study the origin of a preferred nucleation site on the atomically flat 3C-SiC mesas leading to the formation of tetrahedral hillocks. The hillocks exhibit a “wedding cake” structure consisting of concentric triangular terraces with a step height of 0.25nm corresponding to the thickness of a single Si-C bilayer. KOH etching revealed the presence of a threading dislocation at the center of the hillock. Its Burgers vector was shown to lie in the basal plane with no component along the surface normal. It is argued that the strain fields around a threading edge dislocation make it a preferred nucleation site. ► Repeated nucleation of epitaxial 3C-SiC at particular sites formed tetrahedral hillocks. ► The hillocks had triangular concentric terraces with 0.25nm step height. ► The hillocks were produced at a threading edge dislocation. ► Dislocation-induced strain is hypothesized to be responsible of the preferred nucleation.