Transition from Island Growth to Step-Flow Growth for Si/Si(100) Epitaxy

Scanning tunneling microscopy measurements during growth at high substrate temperatures (500–800 K) are used to study the transition from two-dimensional island growth to step-flow growth of Si on Si(100). The presence of surface reconstructions leads to complex behavior in the transition region. In particular, the theoretically predicted transient growth mode, with an oscillatory behavior of the fractional coverages of each of the nonequivalent $(1\times 2)$ and $(2\times 1)$ reconstruction domains, is found experimentally. Comparisons of experimental results with kinetic Monte Carlo simulations show that the speed of biatomic step formation is related to the growth rate-dependent sticking coefficients at the step edges.