Numerical calculation with empirical interatomic potential for formation mechanism of CuAu-I type ordered structure in InGaAsr 110/InP

In an InGaAsr 110.InP, a CuAu-I type ordered structure is formed during growth with a propagation of two-monolayer steps 2-MLSs.. The numerical calculation with an empirical interatomic potential has suggested that the ordered InGaAs clusters are stabilized at kink edges of the 2-MLSs. We confirmed that In and Ga adatoms preferentially occupy the upper and lower sites at a kink of 2-MLS, respectively. This explains that the CuAu-I type ordered structure which is made of alternately stacked In- and Ga-rich 110.planes is formed by propagation of the 2-MLS with kinks. Our Monte Carlo simulation using the ordering model showed that the ordered structure is actually formed at the growth temperature ;700 K.. q2000 Elsevier Science B.V. All rights reserved