ENHANCED CURRENT INJECTION IN THERMAL OXIDES GROWN ON TEXTURIZED SILICON

A new technique to achieve enhanced current injection in SiO//2 layers thermally grown on texturized monocrystalline Si surfaces is presented. Sites of local field enhancement are created at the Si-Sio//2 interface by anisotropic chemical etching of the Si surface prior to oxidation. Current-voltage characteristics measured on MOS capacitor structures having a 60 nm thick dry thermal oxide grown at 1000 degree C follow a Fowler-Nordheim law over more than 5 decades of current and exhibit local field enhancement factors in the range 1-8 (exceptionally up to 13), depending on the etching conditions used. These high field enhancement factors lead to a reduction of the average field necessary to inject a current density of 10** minus **8 A/cm**2 to values in the range from 1. 5 to 2. 3 MV/cm for textured interface oxides as compared to values in excess of 7 MV/cm for smooth interface oxides grown under identical conditions.