Spin-on silicon oxide (SOX): A new low temperature dielectric.

This paper describes a new approach to a low-temperature application of silicon oxide. A sol/gel of silica in butanol solution is spin-coated on silicon wafers and cured at 210C or higher to give SiO(2)-like films with an index of refraction between 1.33 and 1.44, depending on conditions. A single application of SOX gives 2300 to 3000angstroms thick film. The oxide has a dielectric breakdown of 6-8 Mv/cm, a tensile stress of ~1x10 (9) dyne cm(-2) per 100 nm of film, dry etching characteristics similar to those of plasma-oxide (RIE rates of ~500angstroms/min in CHF(3)/CO(2) and ~10angstroms/min in CO(2)), and a wet etching rate in 30:1 BOE of ~8000angstroms/min.