Observation of in-plane asymmetric strain relaxation during crystal growth and growth interruption in InGaAs/GaAs(001)

InGaAs/GaAs(001)の結晶成長及び成長中断中における面内非対称的なひずみ緩和の観察

佐々木 拓生*; 下村 憲一*; 鈴木 秀俊*; 高橋 正光; 神谷 格*; 大下 祥雄*; 山口 真史*

Sasaki, Takuo*; Shimomura, Kenichi*; Suzuki, Hidetoshi*; Takahashi, Masamitsu; Kamiya, Itaru*; Oshita, Yoshio*; Yamaguchi, Masafumi*

In-plane asymmetric strain relaxation in lattice-mismatched InGaAs/GaAs(001) heteroepitaxy is studied by three-dimensional X-ray reciprocal space mapping. Repeating crystal growth and growth interruptions during measurements allows us to investigate whether the strain relaxation is limited at a certain thickness or saturated. We find that the degree of relaxation during growth interruption depends on both the film thickness and the in-plane directions. Significant lattice relaxation is observed in rapid relaxation regimes during interruption. This is a clear indication that relaxation is kinetically limited. In addition, relaxation along the [110] direction can saturate more readily than that along the [10] direction. We discuss this result in terms of the interaction between orthogonally aligned dislocations.