The use of electron back-scattered diffraction to study the regrowth of amorphised silicon-based heterostructures

Abstract

Electron back-scattered diffraction (EBSD) patterns are produced by inelastically scattered electrons and are intimately related to the local crystal orientation and quality. Analysis of the EBSD patterns is a rapid, non-destructive technique, which we have used to follow the regrowth of amorphised silicon-based heterostructures. The effective spatial resolution is 80nm, and we show that the technique can detect buried amorphous and oxide layers. Cross-sectional transmission electron microscopy (XTEM) studies confirm the EBSD results. A gas source MBE-grown Si1−xGex (x=14.5%) multi-quantum-well structure with good optical properties was implanted with an amorphising dose of either Si or Er, or Si followed by Er. The structure was annealed at 560°C under flowing N2 and regrowth was monitored at intervals by EBSD. It was found that structures implanted only with Er regrew faster than those implanted only with Si. As expected, the sample implanted with both Si and Er showed regrowth kinetics in between the two.