Observation of the interfacial layer in HfO2(10 nm)/Si by high-resolution RBS in combination with grazing angle sputtering

Abstract

A Si(001) wafer with a HfO2 layer of 10nm thickness prepared by atomic layer CVD, is irradiated by 1keV Xe+ ions at a grazing angle of 15°. The sample is measured in situ using high-resolution Rutherford backscattering spectroscopy. With removing a part of HfO2 layer by the grazing angle sputtering, the observed trailing edge of Hf signal becomes sharper, indicating an improvement of the depth resolution at the HfO2/Si interface. After removal of a part of the HfO2 layer (∼7nm), the effective depth resolution becomes more than two times better than that before sputtering and the existence of the SiOx interface layer is clearly seen.