Positron beam technique for the study of defects at the Si/SiO2 interface of a polysilicon gated MOS system

This work demonstrates that positrons implanted into a 60 nm n-type polysilicon layer with large grains, can be pushed out of this layer by an externally induced electric field. In the case of a metal-oxide-silicon (MOS) system with a such a polysilicon gate, polysilicon-implanted positrons can be efficiently transported towards the SiO2/Si interface where they all are collected. This technique offers new and interesting possibilities to study defects at the SiO2/Si interface of technologically important MOS systems.