Monolayer incorporation of nitrogen at Si–SiO2 interfaces: Interface characterization and electrical properties

This article presents a low-temperature plasma-assisted approach for the preparation of Si–SiO2 interfaces with monolayer concentrations of bonded nitrogen atoms (N atoms) at that interface. Localization of N atoms at Si–SiO2 interfaces has been established by on-line Auger electron spectroscopy (AES), off-line secondary ion mass spectrometry, and optical second harmonic generation. On-line AES studies have established that excess suboxide bonding in interfacial transition regions occurs during plasma-assisted oxidation using N2O and O2 source gases, and that a postoxidation rapid thermal anneal at 900 °C for 30 s in an inert ambient reduces the concentration of these suboxide bonding groups. Defect generation at plasma nitrided interfaces in field effect transistor devices is reduced compared to similar devices in which Si–SiO2 interfaces are formed by furnace oxidation in O2.