Characterizations of Ultra-thin Dielectrics Grown by Microwave Afterglow O₂/N₂O Plasma Oxidation at Low Temperature with Rapid Thermal Annealing

Abstract

Microwave afterglow plasma oxidation at a low temperature (600 °C ) and rapid thermal annealing (RTA) were combined to grow high quality ultra-thin dielectrics. This new approach has a low thermal budget. The mid-gap interface state density of oxides pretreated in N 2 0 plasma was decreased to about 5 X 1010 cm-2 eV-1 after rapid thermal annealing at 950 °C. It was found that RTA is very effective for relieving the oxide stress and reducing the interface state density. Nitrogen incorporated in oxides by the N 2 0 plasma pretreatment of the Si surface helped to reduce the interface state density. Microstructures of ultra-thin oxide grown by microwave afterglow oxidation with or without RTA were revealed by extended-X-ray-absorption-finestructure (EXAFS) and X-ray photoelectron spectroscopy (XPS) analysis.