Performance and reliability improvements in SiC(0001) MOS devices via two-step annealing in H2/Ar gas mixtures

Abstract

While nitric oxide annealing is a standard technique for improving the performance of silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors, degradation of reliability remains a serious issue. Here, we present an alternative approach based on diluted hydrogen annealing, a process widely employed in silicon MOS technology. The key point of our approach is 2-step high-temperature hydrogen annealing before and after gate oxide deposition. A low interface state density (3.2 × 1011eV−1 cm−2) was obtained near the conduction band edge of SiC (Ec − E = 0.2 eV). High peak channel mobility (17.2 cm2 V−1 s−1) and improved reliability against positive and negative bias stress were confirmed.