Structural and compositional study of Si1-xGex multilayer structures using medium energy ion scattering

ABSTRACTThe ability to determine structural and compositional information from the sub-surface region of a semiconductor material has been demonstrated using a new time-of-flight medium energy ion scattering spectroscopy (ToF-MEISS) system. A series of silicon-silicon/germanium (Si/Sil-xGex) hetero-structure and multilayer samples, grown using both solid source molecular beam epitaxy (MBE) and gas source chemical vapour deposition (CVD) on Si(100) substrates, have been investigated. These data indicate that each individual layer of Sil-xGex can be uniquely identified with a depth resolution of approximately 3 nm. A comparison of MBE and CVD grown samples has also been made using layers with similar structures and composition and the results compared with conventional Rutherford back-scattering spectrometry (RBS).