[25p-E301-1~8] CS.9 Code-sharing Session of 13.7 & 15.6

[25p-E301-1] Atomic structure of steps on vicinal SiC(0001) surfaces

〇(PC)Kaori Seino^1,2, Atsushi Oshiyama¹ (1.Nagoya Univ., 2.Jena Univ.)

Keywords:SiC, first-principles calculations, surface step

We have performed real-space density-functional calculations that reveal the atomic structure of steps on vicinal Si-face SiC(0001) surfaces. We have done detailed structural optimization for possible mono-bilayer straight atomic steps along the <1-100> and <11-20> directions on SiC surfaces and found the peculiar structural reconstruction near step edges among the upper and lower edge atoms. The calculated step formation energies of all the possible atomic steps were also considered and show that the straight <1-100> step is energetically more favorable than the <11-20> straight step. Thus, the energetics that obtained for the microscopic viewpoint provides a natural and persuasive macroscopic reason for the difference in the step morphology, e.g., meandering steps for the <11-20> direction, observed experimentally. Moreover, we report the atomic-scale mechanisms of surface diffusion of adatoms on the SiC(0001) stepped surfaces.