Thermal oxidation of 3C silicon carbide single-crystal layers on silicon

Abstract

Thermal oxidation of thick single-crystal 3C SiC layers on silicon substrates was studied. The oxidations were conducted in a wet O2 atmosphere at temperatures from 1000 to 1250 °C for times from 0.1 to 50 h. Ellipsometry was used to determine the thickness and index of refraction of the oxide films. Auger analysis showed them to be homogeneous with near stoichiometric composition. The oxide growth followed a linear parabolic relationship with time. Activation energy of the parabolic rate constant was found to be 50 kcal/mole, while the linear rate constant was 74 kcal/mole. The latter value corresponds approximately to the energy required to break a Si–C bond. Electrical measurements show an effective density of 4–6×1011 cm−2 for fixed oxide charges at the oxide-carbide interface, and the dielectric strength of the oxide film is approximately 6×106 V/cm.