Improved 4H-SiC metal oxide semiconductor interface produced by using an oxidized SiN gate oxide that had undergone post-oxidation annealing

Abstract

We investigated oxidized SiN gate oxides that have undergone post-oxidation annealing (POA) treatment using diluted O2 (10% O2 in N2) at 1100 °C. The oxidized SiN/SiC interfaces were characterized by using capacitance-voltage (C-V) measurements, Auger electron spectroscopy (AES), high-resolution transmission electron microscopy (HR-TEM), and X-ray photoelectron spectroscopy (XPS). POA for 60 min significantly improved the interface trap density (D it ), near-interface trap density (N it ), and effective oxide charge density (Q eff ) of the oxidized SiN. However, improvement was not observed for the as-oxidized SiN sample or the oxidized SiN sample that had undergone POA for 120 min. The electrical properties of metal-oxide semiconductor devices fabricated using these oxides are discussed in terms of the oxide chemical composition.