Structure of the metallic Si(001) surface at high temperatures: Synchrotron x-ray scattering measurements

Abstract

The structure of the metallic Si(001) surface above 900 K was investigated by synchrotron x-ray scattering. Above 900 K, the (2, 1) integer-order surface peak decreases anomalously while the (3/2, 0) reconstruction order peak increases. These results together with the behavior of the crystal truncation rod profile exclude the structural models of the metallic Si(001) surface based on the enhanced Debye-Waller factor and the transition to the symmetrical dimer. The experimental results are explained by the enhanced dynamic step-edge fluctuations induced by the adatom attachments and detachments above 900 K.