Anomalous double-layer step formation on Si(100) in hydrogen process ambient

Abstract

We prepared Si(100) surfaces with anomalous atomic double-layer steps grown via chemical vapor deposition. Scanning tunneling microscopy resolved ${D}_{A}$-type steps, supported by low-energy electron diffraction, Fourier-transform infrared spectroscopy, and in situ reflection anisotropy spectroscopy, which enabled direct control of majority domain formation. We attribute the energetically unfavorable step structure to interaction of the surface with the H${}_{2}$ ambient, driving a dynamic step formation process governed by surface vacancy generation, diffusion, and annihilation at step edges.