A new technique to achieve enhanced current injection in layers thermally grown on texturized monocrystalline Si surfaces is presented. Sites of local field enhancement are created at the 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°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 −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. Characteristics of both texturized and smooth interface capacitors, measured after injecting a total charge of , exhibit a slight shift of ∼0.4 MV/cm to higher fields. The behavior of both types of oxides following field stress is similar, indicating that the trapping characteristics of the oxide are not degraded by the surface texturization. The method presented constitutes a promising alternative to other current enhancement techniques, based for example on the use of polysilicon oxides or off‐stoichiometric films, which are presently under investigation for EEPROM‐type memory cell applications.
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Olcer et al. (1986) studied this question.