Abstract:

The time τ necessary for the formation of bumps due to thermal fluctuations on steps of vicinal surfaces is evaluated in various relevant cases. Formulae already derived by Mullins and Bales and Zangwill and other expressions recently published by Bartelt et al., are found as special cases. For Si(111) at 900°C we predict that τ is proportional to the step-step separation l and to the square of the fluctuation wavelength L. This prediction is found to be in reasonable agreement with direct experimental observations of equilibrium step fluctuations.