Superjunction semiconductor device and manufacturing method of superjunction semiconductor device

摘要

Problem to be solved: to provide an ultra junction semiconductor device capable of reducing an ion implantation step for forming a base region and a method of manufacturing an ultra junction semiconductor device.The super junction semiconductor device comprises a silicon carbide semiconductor substrate 1 of a first conductivity type, a first semiconductor layer 2 of a first conductivity type, a first trench 30 provided in the first semiconductor layer 2, a bottom surface continuous to an opening of the first trench 30, opening in the upper surface of the first semiconductor layer 2, and a first Torre A second trench 31 having a width wider than that of the knee 30 is provided.The third semiconductor region 6 of the second conductivity type is provided inside the first trench 30, and the second semiconductor region 3 of the second conductivity type is provided inside the second trench 31.A fifth semiconductor region 7 having a higher impurity concentration than the third semiconductor region 6 is provided in the third semiconductor region 6.A gate trench 18 extends through the third semiconductor region 6 and the fifth semiconductor region 7 to reach the first semiconductor layer 2.Diagram