Selection of growth monomers on the 4H-SiC (0001) atomic step surfaces: From the first-principles calculations to homo-epitaxy verification

Abstract

Silicon carbide (SiC) has gained increased interest due to industry demand, especially for the 4H-SiC. Nevertheless, the ‘structural mutation’ in the 4H-SiC epitaxy is in urgent need of investigation and proper solution as the epitaxial thickness/wafer size increases. In this study, growth monomers in the step-flow mode were firstly investigated by the first-principles calculations for their dynamic and kinetic behaviours from an atomic level. The stability (by the comprehensive analyses of total energies, chemical potentials, and formation enthalpies) and the location of adsorptions were studied to reveal the dynamics. Meanwhile, the potential barrier of Si-Si interaction and phonon spectra were determined to understand the kinetics. We found monomers could be selected by controlling chemical potentials to make ordering growth. Secondly, two methods were thus inferred to select monomers to adsorb on atomic step surfaces in an orderly fashion and were verified in a six-inch epitaxy. Thirdly, a protocol was designed to restrict the extension of basal plane dislocation (BPD) from substrates, a reduction greater than five orders of magnitude was gained but without time compromise in the thick-film epitaxy. This study provided new insights into growth on the 4H-SiC (0001) atomic step surfaces and a new way of 4H-SiC homo-epitaxy.