Yoshihiro Kangawa1, Noriyuki Kuwano2,Kensuke Oki2 and Tomonori Ito3
1Department of Materials Science and Technology, Graduate School of Engineering Sciences, Kyushu University, Fukuoka 816-8580
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.
(Received January 12, 1999; In Final Form March 24, 1999)
InGaAs, CuAu-I type ordered structure, empirical interatomic potential, epitaxial growth, two-monolayer step, alloy semiconductor
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