Europhysics Letters, 19 (1) pp 33-38 (1992)

A Model for Strain-Induced Roughening and Coherent Island Growth

B. G. Orr, D. Kessler, C. W. Snyder and L. Sander

We have investigated the morphological evolution of strained films during 
growth. Novel Monte Carlo studies, which incorporate linear elasticity, 
have been performed to simulate film growth with misfit. These studies 
demonstrate the onset of islanding for sufficiently large misfit. We 
present an analytic calculation which shows that from the onset of 
deposition the films are energetically unstable to large-scale islanding. 
We argue that the kinetics ultimately determines the surface morphology. 
Dislocations are not necessary for surface lattice relaxation. Support for 
this picture is inferred from experimental results on a number of strained 
growth systems.