Metastabile and Multiply-Charged Individual Defects at the Si:SiO₂ Interface

Abstract

In small-area silicon metal-oxide-semiconductor field-effect transistors (MOSFETs), the fluctuating occupancy of individual Si:SiO₂ interface states generates Random Telegraph Signals (RTSs) in the drain current. We have observed a new class of RTS which exhibits anomalous behaviour. We demonstrate that these signals are due to individual interface states which can exist in two or more charge-equivalent metastable states. We present results on a single defect which exhibits two-electron capture, metastability and negative-U-like behaviour.