TUNNEL OXIDE PREPARED BY THERMAL-OXIDATION OF THIN POLYSILICON FILM ON SILICON (TOPS)

This letter presents a textured tunnel oxide, TOPS, prepared by thermally oxidizing a thin polysilicon film on a Si substrate. Due to the rapid diffusion of oxygen through the grain boundaries of the thin polysilicon into Si substrate and the enhanced oxidation rate at the grain boundaries, a textured Si/SiO2 interface is obtained. The textured interface results in the localized high fields and enhances electron injection into TOPS. The TOPS exhibits a higher electron injection efficiency, a better immunity to the electron trapping and the interface state generation under the high-field operation, and a higher asymmetric injection polarity as compared to the normal oxide.