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

in an InGaAs/(110)InP, a CuAu-I type ordered structure is formed during gro wth with a propagation of two-monolayer steps (2-MLSs). The numerical calcu lation with an empirical interatomic potential has suggested that the order ed 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 s tructure 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 simulatio n using the ordering model showed that the ordered structure is actually fo rmed at the growth temperature (similar to 700 K). (C) 7000 Elsevier Scienc e B.V. All rights reserved. PACS: 68.55 (Epitaxy); 68.35.R (Phase transitio ns at surface and interfaces); 73.61.J (Semiconductor thin films); 07.05.T (Computer modeling and simulation).