Crystal growth dynamics studied using in situ X-ray diffraction; Zero-, one- and two-dimensional structures

Takahashi, Masamitsu; Hu, W.; Kozu, Miwa*; Sasaki, Takuo*; Oshita, Yoshio*; Suzuki, Hidetoshi*

Growth dynamics of semiconductor nanostructures ranging from quantum wells to quantum dots will be discussed on the basis of in situ X-ray diffraction. Experiments were performed using a molecular-beam epitaxy (MBE) chamber integrated with an X-ray difftactometer at 11XU of SPring-8. First, of all the nanostructures, quantum wells are playing the most important roles in technological applications today. For in situ study of growth of quantum wells, we have developed a real time X-ray technique enabling three-dimensional reciprocal space mapping during growth and applied it for the investigation of InGaAs growth on GaAs(001). Second, quantum wires are recently attracting much interest because of their extremely anisotropic one-dimensional shape. In this paper, we will present in situ X-ray diffraction data during the As-assisted vapor-liquid-solid growth of GaAs nanowires. Finally, the growth of quantum dots, which are the ultimate quantum structure, will be discussed as well.