原子間ポテンシャルを用いたInGaAs/(110)InP混晶中に出現するCuAu-I型規則構造形成機構の理論的解析

抄録

It is known that a CuAu-I (L1₀) type ordered structure is formed in an (In, Ga)As alloy semiconductor grown on a slightly tilted (110)InP substrate. The energy gains due to the formation of L1₀ in a bulk alloy, in a thick epi-layer and in a single epi-layer on a two-monolayer step, were investigated using an empirical interatomic potential calculation. It is confirmed that an L1₀ ordered structure is not stable in a bulk alloy. The ordered structure can exist stably in a thick epi-layer, but the energy gain due to the ordering is too small to form the ordered structure at the growth temperature. The L1₀ ordered structure can actually form at a two-monolayer step on the growth-surface. This indicates that the atomic arrangement near the two-monolayer step has strong effects on the stability of the ordered structure in an (In, Ga)As alloy.