From thin film to bulk 3C-SiC growth: Understanding the mechanism of defects reduction

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

Protrusions reduction in 3C-SiC thin film on Si

In this letter, we have studied the density of microtwins in the vicinity of the film surface, by using in-plane grazing incidence diffraction technique, to suggest a reduction trend of such defects at different growth rates. In (100) 3C–SiC heteroepitaxy, microtwin density decreases when a slower growth rate process is performed. A reduction ratio of microtwins of 0.16, 0.2, and 0.28 for 2 μm/h, 5 μm/h, and 10 μm/h, respectively, has been obtained. The relationship between microtwin density and growth rate, or Si/H2 ratio, found with this technique is in perfect agreement with the pre-existent literature.

Microtwin reduction in 3C–SiC heteroepitaxy

An important issue in the technology of cubic SiC (3C-SiC) material for electronic device applications is to understand the behavior of extended defects such as partial dislocation complexes and stacking faults. Atomistic simulations using molecular dynamics (MD) are an efficient tool to tackle this issue for large systems at comparatively low computation cost. At this, proper choice of MD potential is imperative to ensure the reliability of the simulation predictions. In this work, we compare the evolution of extended defects in 3C-SiC obtained by molecular dynamics simulations with Tersoff, analytical bond order, and Vashishta potentials. Key aspects of this evolution are considered including the dissociation of 60° perfect dislocations in pairs of 30O and 90O partials as well as the dependence of the partial dislocation velocity on the Burgers vector and the atomic composition of core. Tersoff potential has been found to be less appropriate in describing the dislocation behavior in 3C-SiC as compared to two other potentials, which in their turn provide qualitatively equivalent predictions. The Vashishta potential predicts much faster defect dynamics than the analytical bond order potential (ABOP). It can be applied therefore to describe the large-scale evolution of the dislocation systems and stacking faults. On the other hand, ABOP is more precise in predicting local atom arrangements and reconstructions of the dislocation core structures. In this respect, synergetic use of ABOP and Vashishta potential is suggested for the molecular dynamics simulation study of the properties and evolution of extended defects in the 3C-SiC.

/pdf/molecular-dynamics-simulations-of-extended-defects-and-their-wwigo494vh.pdf

Molecular dynamics simulations of extended defects and their evolution in 3C-SiC by different potentials

3C-SiC epitaxial layers were grown by sublimation epitaxy in a vacuum on the (0001)C face of 6H-SiC substrates produced by the Lely method and 4H-SiC substrates grown by modified Lely method. An analysis of these layers demonstrated the high structural perfection of the epitaxial layers and absence of any transition regions between 3C-SiC epitaxial layer and substrate. The low-temperature conductivity and magnetoresistance of the films have been studied in relation to their doping level and structural perfection.

Dmitrii V. Shamshur

Papers

Influence of the defect density (twins boundaries) on electrical parameters of 3C-SiC epitaxial films