Roughening rates of strained-layer instabilities

Phys Rev Lett. 2005 Feb 18;94(6):066101. doi: 10.1103/PhysRevLett.94.066101. Epub 2005 Feb 14.

Abstract

We study the evolution of the morphology of Si0.75Ge0.25 strained layers using a wide range of deposition times, 60<tau<2400 s, at 600 degrees C on laser textured substrates with miscuts theta<15 degrees off Si(001). Ripple-shaped morphologies form spontaneously on miscuts along the 110 directions. At the shortest deposition times, roughening is suppressed as predicted by a linear stability analysis that uses previously measured values for the mass transport rate on the surface. The measured time constant of the roughening is approximately 80 s, a factor of 4 larger than predicted by theory.