Direct observation of electrically active interfacial layer defects which may cause threshold voltage instabilities in HfO2 based MOSFETs

Recent studies have demonstrated that deep level defects very near the Si/dielectric boundary are important reliability problems in HfO₂ based devices. In this study, we provide a partial identification of the chemical and structural nature of an electrically active center which is present in the interfacial layer of HfO₂ based devices. The defect almost certainly involves an oxygen deficient silicon which is weakly coupled to a nearby hafnium atom.