FORMING METHOD OF DUAL GATE OXIDE FILM AND MANUFACTURING METHOD OF SEMICONDUCTOR ELEMENT UTILIZING THE FILM

PROBLEM TO BE SOLVED: To provide a forming method of a dual gate oxide film, in which twice thermal processes or ion injection which may cause the complexity of processes and damages to a semiconductor substrate are not required, and a manufacturing method of a semiconductor element utilizing the forming method. SOLUTION: The manufacturing method of the semiconductor element comprises a step, forming a gate oxide film 23 on the semiconductor substrate 21, and another step, increasing the thickness of a part of the gate oxide film by treating the part of the gate oxide film through a decoupled plasma treatment. COPYRIGHT: (C)2003,JPO