| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method of a semiconductor device which does not allow an unnecessary trench to be formed on a surface of a trench structure and which can improve area efficiency of an element.SOLUTION: A manufacturing method of a semiconductor device including a trench structure in which polysilicon is filled in trenches and an upper part of the polysilicon is covered with a silicon oxide film, comprises: a trench formation process of performing anisotropic etching on a substrate on which a first silicon oxide film is laminated on top face of a silicon activation layer to form trenches extending from the top face of the first silicon oxide film to inside the silicon activation layer; a lateral wall oxide film formation process of forming a second silicon oxide film integrally covering the whole of lateral walls of the trenches; a filling process of filling polysilicon in the trenches after forming the second silicon oxide film; and a cap formation process of forming a cap by oxidization of an upper exposed surface of the polysilicon filled in the trenches. |
