METHOD FOR FORMING GATE OXIDE LAYER TO REDUCE LEAKAGE CURRENT USING INSULATING LAYER WITH HIGH PERMITTIVITY

摘要

PURPOSE: A method for forming a gate oxide layer is provided to reduce leakage current due to direct tunneling by using an insulating layer with high permittivity, such as La2O3. CONSTITUTION: An La thin film is formed on a silicon substrate(21). An La2O3 layer(23a) as a gate oxide layer is then formed by oxidation processing of the La thin film. A gate structure(33) including a polysilicon layer(27a), a tungsten film(29a), a nitride hard mask(31a) is formed on the La2O3 layer. A source(37) and a drain(39) are formed in the substrate.