Random telegraph signals originating from unrelaxed neutral oxygen vacancy centres in SiO2

Unrelaxed neutral oxygen deficiency centres (ODCs) (V⁰ ODC II) in SiO₂ have been identified as the cause of random telegraph signals (RTSs) in highly scaled n-type metal-oxide-semiconductor field-effect transistors. Variable temperature RTS measurements were performed to extract trap capture cross-sections, capture activation energy, relaxation energy associated with the gate oxide defects, and the trap energy in the SiO₂ bandgap to determine the trap species and type. The results indicate that the electron is captured by a neutral ODC that is transformed into a negatively charged vacancy (V^-). This is the first time V⁰ ODC II centre is confirmed to be the source of electron switching through RTS measurements defining four different trap characteristics.