Scanning tunneling microscopy studies during semiconductor growth

A scanning tunneling microscope (STM), capable of imaging during semiconduc tor growth, is described. The method (MBSTM) opens the possibility to follo w the growth process of semiconductor molecular beam epitaxy (MBE) during g rowth. The ability of the microscope to access the evolution of the growth morphology down to the atomic level is demonstrated by the following result s: In Si/Si(111) homoepitaxy, lateral growth of islands occurs along stripe s of the width of a (7 x 7) unit cell. In Ge/Si(111) heteroepitaxy atomic l ayer-by-layer growth of Ce on Si(111) and the subsequent formation of three -dimensional (3D) islands are observed. During the subsequent growth of 3D islands, an inversion of the aspect ratio of islands indicates a transition from strained islands to islands with misfit dislocations. (C) 1999 Elsevi er Science Ltd. All rights reserved.