Structural defects in SiO2/SiC interface probed by a slow positron beam

Abstract We studied structure of SiO 2 /SiC interfaces grown by thermal oxidization using low energy positron beams. From the positron lifetime measurements, typical two lifetime components related to amorphous network and large open spaces are observed in SiO 2 , while only bulk lifetime in SiC. The lifetime of positrons near the interface is similar to that of SiO 2 amorphous network and no lifetime components related to large open spaces are detected. From the Doppler broadening measurements, the momentum distribution, probably related to oxygen valence electrons, is enhanced near the interface. The above results imply that the interface region has less open spaces than SiO 2 involving many oxygen dangling bonds.