Kinetics of Si growth from hydride precursors on As-passivated Si(001) surface

Abstract

The presence of arsenic on a Si(001) surface is known to have a strong effect on the growth rate during epitaxial growth of silicon from hydride precursors. In this letter, the authors describe a study of this effect using the reflection high energy electron diffraction (RHEED) intensity oscillation technique. A number of surface As coverages produced by cycles of arsine adsorption at temperature below 400°C and hydrogen desorption at 600°C were considered. The period of the first RHEED intensity oscillation during overgrowth on a partially As-passivated Si(001) surface is found to be proportional to that during homoepitaxy. The constant of proportionality is equal to the inverse of the fraction of the clean Si surface not passivated by As. This experimental finding is explained using a model based on rate equations for surface hydrogen coverage and site exclusion by arsenic. © 2001 American Institute of Physics.