Initial stage growth of Ge(x)Si(1−x) layers and Ge quantum dot formation on Ge(x)Si(1−x) surface by MBE

Critical thicknesses of two-dimensional to three-dimensional growth in Ge(x)Si(1−x) layers were measured as a function of composition for different growth temperatures. In addition to the (2 × 1) superstructure for a Ge film grown on Si(100), the Ge(x)Si(1−x) layers are characterized by the formation of (2 × n) reconstruction. We measured n for all layers of Ge/Ge(x)Si(1−x)/Ge heterosystem using our software with respect to the video recording of reflection high-energy electron diffraction (RHEED) pattern during growth. The n reaches a minimum value of about 8 for clear Ge layer, whereas for Ge(x)Si(1−x) films, n is increased from 8 to 14. The presence of a thin strained film of the Ge(x)Si(1−x) caused not only the changes in critical thicknesses of the transitions, but also affected the properties of the germanium nanocluster array for the top Ge layer. Based on the RHEED data, the hut-like island form, which has not been previously observed by us between the hut and dome islands, has been detected. Data on the growth of Ge/Ge(x)Si(1−x)/Ge heterostructures with the uniform array of islands in the second layer of the Ge film have been received.