Structure and Stability of Partial Dislocation Complexes in 3C-SiC by Molecular Dynamics Simulations.

Andrey Sarikov,Anna Marzegalli,Francesco Montalenti,Luca Barbisan,Leo Miglio

doi:10.3390/ma12183027

Abstract

In this work, the structure and stability of partial dislocation (PD) complexes terminating double and triple stacking faults in 3C-SiC are studied by molecular dynamics simulations. The stability of PD complexes is demonstrated to depend primarily on the mutual orientations of the Burgers vectors of constituent partial dislocations. The existence of stable complexes consisting of two and three partial dislocations is established. In particular, two types of stable double (or extrinsic) dislocation complexes are revealed formed by two 30° partial dislocations with different orientations of Burgers vectors, or 30° and 90° partial dislocations. Stable triple PD complexes consist of two 30° partial dislocations with different orientations of their Burgers vectors and one 90° partial dislocation, and have a total Burgers vector that is equal to zero. Results of the simulations agree with experimental observations of the stable PD complexes forming incoherent boundaries of twin regions and polytype inclusions in 3C-SiC films.

Highlights

Properties of cubic silicon carbide (3C-SiC) that combine a large band gap value as compared to that of Si (2.35 vs. 1.1 eV) [1], high bulk and channel electron mobility [2,3], and low trap density at the 3C-SiC/SiO2 interfaces of the metal-oxide-semiconductor structures [4] make it one of the most suitable candidates for power MOSFET devices in the range of breakdown voltages below 800 V for hybrid electric vehicles, air conditioning, and LED lighting system applications [5,6]
In our previous publication [17], we demonstrated that molecular dynamics (MD) simulations with analytical bond order (ABOP) [18] and Vashishta [19] potential applied synergetically are an efficient tool to model the behavior of extended defects, such as stacking faults and dislocations, in cubic silicon carbide
ResultsIn this section, we present the results of the molecular dynamics simulations of the interaction of partial dislocations (PDs) terminating stacking faults, which for certain combinations of the Burgers

Summary

Introduction

Properties of cubic silicon carbide (3C-SiC) that combine a large band gap value as compared to that of Si (2.35 vs. 1.1 eV) [1], high bulk and channel electron mobility (up to 1000 and 250 cm2 /Vs, respectively) [2,3], and low trap density at the 3C-SiC/SiO2 interfaces of the metal-oxide-semiconductor structures [4] make it one of the most suitable candidates for power MOSFET devices in the range of breakdown voltages below 800 V for hybrid electric vehicles, air conditioning, and LED lighting system applications [5,6]. Various kinds of extended defects, such as microtwins, antiphase boundaries, and stacking faults (SFs), develop at the Si/3C-SiC interface, induced by stress release processes, and propagate into the 3C-SiC films during growth. Concentrations of these defects decrease with the increase of the film thickness by a self-annihilation mechanism; some of them (e.g., microtwins) may even completely disappear in very thick 3C-SiC layers [6,8]. Partial dislocations should be given particular attention as they are important components of the microstructure of bulk semiconductors, like the 3C-SiC considered in this work, and of advanced material structures, such as 2d materials, crucially influencing their conductivity and mechanical characteristics [11,12]

Methods

Results

Discussion

Conclusion