Extended defects in 3C-SiC: Stacking faults, threading partial dislocations, and inverted domain boundaries

The presence of extended bi-dimensional defects is one of the key issues that hinder the use of wide band-gap materials hetero-epitaxially grown on silicon. In this work, we investigate, by STEM measurements and molecular dynamic simulations, the structure of two of the most important extended defect affecting the properties of cubic silicon carbide, 3C-SiC, hetero-epitaxially grown on (001) silicon substrates: (1) stacking faults (SFs) with their bounding threading dislocation arms, even along with unusual directions, and (2) inverted domain boundaries (IDBs). We found that these two defects are strictly correlated: IDBs lying in {111} planes are intrinsically coupled to one or more SFs. Moreover, we observed that threading partial dislocations (PDs), limiting the SFs, appear to have non-conventional line directions, such as [112], [123], and [134]. Molecular dynamics simulations show that [110] and [112] directions allow for stable dislocation structures, while in the unusual [123] and [134] directions, the PDs are composed of zig-zag dislocation lines in the [112] and [110] directions. (c) 2021 Published by Elsevier Ltd on behalf of Acta Materialia Inc.

Automated summary

This work investigated the structure of two major extended defects affecting the properties of cubic silicon carbide by STEM measurements and molecular dynamic simulations. It was found that stacking faults and inverted domain boundaries in 3C-SiC are strictly correlated, with threading partial dislocations having unconventional line directions. Molecular dynamics simulations revealed stable dislocation structures along [110] and [112] directions, while [123] and [134] directions resulted in zig-zag dislocation lines.