Real-time observation of anisotropic strain relaxation by three-dimensional reciprocal space mapping during InGaAs/GaAs(001) growth

InGaAs/GaAs(001)成長中の三次元逆格子マッピングによる非等方的緩和現象の実時間観察

鈴木 秀俊*; 佐々木 拓生*; 崔 炳久*; 大下 祥雄*; 神谷 格*; 山口 真史*; 高橋 正光; 藤川 誠司

Suzuki, Hidetoshi*; Sasaki, Takuo*; Sai, Akihisa*; Oshita, Yoshio*; Kamiya, Itaru*; Yamaguchi, Masafumi*; Takahashi, Masamitsu; Fujikawa, Seiji

Real-time three-dimensional reciprocal space mapping measurement during InGaAs/GaAs(001) molecular beam epitaxial growth has been performed to investigate anisotropy in relaxation processes. Anisotropies, strain relaxation, and crystal quality in [110] and [10] directions were simultaneously evaluated via the position and broadness of 022 diffraction. In the small-thickness region, strain relaxation caused by -dislocations is higher than that caused by -dislocations, and therefore crystal quality along [110] is worse than that along [10]. Rapid relaxation along both [110] and [10] directions occurs at almost the same thickness. After rapid relaxation, anisotropy in strain relaxation gradually decreases, whereas crystal quality along [10] direction, presumably due to -dislocations, becomes better that along [110] direction and the ratio does not decay with thickness.