SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME

摘要

PURPOSE: A semiconductor device and a manufacturing method thereof are provided to improve a withstand voltage between a drain and a gate and to suppress the increase of on-resistance. CONSTITUTION: A second conductive buried layer (2) is formed on a first conductive semiconductor substrate (1). A second conductive epitaxial layer (3) is formed on the second conductive buried layer. A trench (8) is formed on the second conductive epitaxial layer. A first conductive body region (4) is formed around the side of the trench. A gate insulation layer (10) is formed on the inner wall of the trench. A gate electrode (11) is formed by filling the trench with polycrystalline silicon.