Silicon carbide oxidation in the presence of cesium: Modeling and analysis

Abstract

In this work we have focused on investigating the interaction of cesium (Cs) atom/ion with the oxidant and carbon cluster defects at the SiC/SiO2 interface using atomistic scale computational techniques and experimental characterization methods. We observe that Cs behaves significantly different from sodium (Na) at the SiC/SiO2 interface. Our analyses indicate that Cs tends to form a strong bond with the incoming oxygen molecule, leading to the formation of Cs oxide and suboxides. Results suggest that Cs does not reduce the penetration barrier of the impinging oxidant (O2 molecule). Also, unlike Na, Cs is unable to increase the Fermi energy of SiC/SiO2 interface. Finally, lateral metal–oxide–semiconductor field-effect transistors (MOSFETs) were fabricated (using Cs) yielding mobilities less than 1 cm2/V s versus ∼100 cm2/V s fabricated using Na.