Atomic behavior of carbon atoms on a Si removed 3C-SiC (111) surface during the early stage of epitaxial graphene growth

Abstract

The understanding of the formation of graphene at the atomic scale on Si-terminated 3C-SiC for obtaining high-quality graphene sheets remains elusive, although epitaxial graphene growth has been shown to be a well-known method for economical mass production of graphene/SiC heterojunctions. In this paper, the atomic behavior of carbon atoms on a Si removed 3C-SiC (111) surface for the formation of graphene buffer layer during the early stage of epitaxial graphene growth was investigated using a molecular dynamics simulation. Observation of the behavior of the remaining carbon atoms on the Si-terminated 3C-SiC (111) surface after removal of the silicon atoms revealed that graphene clusters, which were formed by sp2-bonded carbon atoms, start to appear at annealing temperatures higher than 1300 K. Our simulations indicated that the structural stability of the whole system increased as the number of sp2-bonded carbon atoms on the Si-terminated 3C-SiC (111) surface increased. It was also found that the diffusion energy barrier for the migration of carbon atoms from the on-top site to the bridge site on the Si-terminated 3C-SiC (111) surface mainly determines the critical temperature of graphene cluster formation.

Atomistic-Scale Simulations of the Graphene Growth on a Silicon Carbide Substrate Using Thermal Decomposition and Chemical Vapor Deposition

“…Recently, significant theoretical efforts have been dedicated to understand the experimental observation for the graphene substrate on the SiC growth. For example, Tang and Hwang et al demonstrated that the graphene-like structure appears at temperatures higher than 1300–1500 K based on their simulation results with Tersoff potential. , Iguchi et al employed Brenner potential to study the effects of temperature and surface orientation on the quality of graphene . Besides, Nemec et al tried to reveal the reason of why graphene growth on the C-terminated SiC surface is very different with that on the Si-terminated face with the help of ab initio calculations .…”

Mechanisms for Graphene Growth on SiO2 Using Plasma-Enhanced Chemical Vapor Deposition: A Density Functional Theory Study

“…For instance, Zhang and van Duin carried out ReaxFF MD simulations to describe both the thermal decomposition of SiC substrates and the CVD growth of graphene layers with a focus on the different temperature regimes. More common results use Tersoff and Brenner interatomic potentials , to characterize the growing shapes of graphene nanostructures or study the effects of temperature or surface geometry . Meagre attempts of using ab initio methods include AIMD simulations of the decomposition of the first layers of SiC substrates or the study of nucleation of different graphene precursors on metallic substrates. , …”

Molecular dynamics simulation of graphene growth by surface decomposition of 6H-SiC(0001) and $(000\bar{1})$

“…10) The mechanism of graphene growth by SiC surface decomposition at the atomic level is not yet well understood. Many investigations of graphene using first-principles [11][12][13][14] and classical molecular dynamics (MD) [15][16][17] simulations have been reported. First-principles methods are powerful tools for the rigorous analysis of energetically stable structures, bonding sites, and band structures, among others.…”