SCANNING TUNNELING MICROSCOPY STUDY OF EPITAXIAL GROWTH OF SI AND GE ON SILICON DURING GROWTH

摘要

We use a scanning tunneling microscope (STM) capable of imaging the growing layer during MBE-growth at high temperatures. This method (MBSTM) opens the possibility to follow MBE growth processes dynamically on the atomic scale and gives access to the evolution of specific features during growth. The influence of surface reconstructions on growth kinetics can be studied directly. For the case of growth of Si islands on Si(111) we find lateral growth of rows of the width of the 7x7 reconstruction unit cell at the edges of twodimensional islands. This leads to a kinetic stabilization of magic island sizes. The evolution of size and shape of individual {105} faceted Ge islands (hut cluster) on Si(001) is measured during growth. A slower growth rate is observed when an island grows to larger sizes. This behavior can be explained by kinetically self-limiting growth.