Reliability of 4H-SiC (0001) MOS Gate Oxide by NO Post-Oxide-Annealing

Abstract

In this work, we investigated the oxide reliability of 4H-SiC (0001) MOS capacitors, the oxide was fabricated about 60 nm by thermal oxidation temperature at 1350°C, the oxides than annealed at different temperatures and times in diluted NO (10% in N2). The 4H-SiC MOS structure was analyzed by C-V and I-V measurement. Compared the J-E curves and Weibull distribution curves of charge-to-breakdown for fives samples under different annealing temperature and time, it shows that the high annealing temperature improves the electrical properties as the lifetime enhanced. The mode value of field-to-breakdown (EBD) for thermal oxides by post-oxide-annealing in NO for 30 min at 1350°C was 10.09 MV/cm, the charge-to-breakdown (QBD) of this sample was the highest in all samples, and the QBD value at 63.2% cumulative failure rate was 0.15 C/cm2. The QBD of the sample annealing at 1200°C for 120 min was 0.06 C/ cm2. The effects of NO annealing in high temperature enhance the lifetime of electrical properties and field-to-breakdown obviously. It can be demonstrated that the annealing temperature as high as 1300°C for 30 min can be used to accelerate TDDB of SiC MOS gate oxide.

Reaction Kinetics Investigation of Ni Ohmic Contacts on N-Type 4H-SiC

“…Due to its higher breakdown field strength, higher saturated drift velocity and higher thermal conductivity compared to silicon (Si), silicon carbide (SiC) has become more promising for the application of high-temperature and high-power electronic devices [1][2][3]. Furthermore, among the typical polytypes of SiC, 4H-SiC is regarded as the most appropriate polytype for fabricating power devices mainly owing to its lower anisotropy and availability of high-quality epitaxial wafers [1].…”