Characterization of GeSi/Si Layer Structure by CBED

Abstract

Recently, there have been growing interests in GeSi/Si heteroepitaxial layers because of their promising optical and electronic properties which can be controlled through changing the composition of the epitaxial layer and hence strain field and defects distribution at the GeSi/Si interface. Thiswork concerns strain field characterization through accurate measurement of lattice parameters across a GeSi/Si interface by CBED. In fact, the accuracy of lattice parameter measurement by CBED lies in that the angular resolution of a HOLZIZOLZ line is in reverse proportion to the amplitude of the relevant G vector. The larger the G vector, the higher the angular resolution is, and the easier the HOLZ line can be blurred by strain and defects.