Characteristics of Sol-Gel Derived SiO2 Thick Film on 4H-SiC

Abstract

Physical and electrical properties of sol-gel derived SiO2 thick film (100-130 nm) deposited on n-type 4H-SiC have been investigated. The oxide was annealed in argon gas ambient for 30 minutes at 650, 750, 850, and 950°C, in order to optimize the oxide properties. Results indicated that the oxide is denser with a significant reduction in percentage of porosity as the annealing temperature increases, except for sample annealed at 950°C. The oxide annealed at 850°C was having values of refractive index and dielectric constant close to the values reported in thermally grown SiO2 and it has demonstrated the lowest leakage current density and total interface trap density. Viscous shear flow effect has been proposed as the main contributor for the reduction of physical properties when the oxide was annealed at 950°C.