Scanning Tunneling Microscopy of Si(100)-c(4×4) Reconstructed Structure Formed by Ethylene Exposure

Abstract

Si(100) surfaces exposed to ethylene (C2H4) at 700°C were observed using a scanning tunneling microscope (STM). For surfaces exposed to 10 L (1 L=1.3×10-4 Pa·s) of C2H4, irregular dots appeared in Si dimer rows, and lines of continuous missing dimers appeared that were aligned perpendicular to the Si dimer rows. With increasing C2H4 exposure, densities of both the irregular dots and the continuous missing dimers, as well as the length of the missing dimer rows, increased. For surfaces exposed to 100 L of C2H4, part of the Si(100)-(2×1) surface was reconstructed to a c(4×4) structure. The c(4×4) domain was located preferentially at the atomic step of a terrace and grew in the direction of the dimer rows in a (2×1) structure. The c(4×4) structure basically consisted of two distinct subunits.