Positron Annihilation Spectroscopy on Open-Volume Defects in Group IV Semiconductors

摘要

In this review of recent results from the positron group at Aalto university, we show how positron annihilation spectroscopy (PAS) can be used for identifying and studying the stability of open volume defects in different Si, Ge and SiGe structures. Some preliminary new results on GeSn are also presented. We show how the electronic states of the E center in SiGe have been determined as well as how thermal stability of this defect can be studied with PAS. In Ge we identify the monovacancy and the divacancy and study their thermal stability. PAS can also be used for studying interface states and this is utilized on Si nanoparticles embedded in SiO_2.