Effect of diatomic islands on step morphological stability of a terrace edge in molecular beam epitaxy

The effect of two-dimensional diatomic-island nucleation on the linear stab ility of the step morphology during molecular beam epitaxy is investigated numerically via shooting methods. It is found that the effect of diatomic i slands on the step morphological stability is significant. The greater the effects of diatomic islands, the more stable the step morphology. increasin g capture efficiency can decrease the critical surface capillary length and shift the critical wave number toward short-wavelength regimes. The unstab le region is shrunk with increasing capture efficiency. Further, increasing flux coverage and/or surface coverage can decrease the critical surface ca pillary length and shift the critical wave number toward short-wavelength r egimes. (C) 1999 Elsevier Science S.A. All rights reserved.