SEMICONDUCTOR DEVICE FOR POWER

摘要

PURPOSE: A semiconductor device for power is provided to increase a switching speed of a semiconductor device for power by improving a structure of the semiconductor device for power. CONSTITUTION: An n- epitaxial layer(55) of low density is formed on an upper portion of a semiconductor layer(50). A gate including gate electrodes(59) and a gate oxide layer(57) is formed on the n- epitaxial layer(55). A p- well region(61) and a p+ well region are formed under a surface of the n- epitaxial layer(55) between the gate electrodes(59). An n+ source region(67) is formed under surfaces of the p- well region(61) and the p+ well region. The first electrode(71) is connected electrically with the p+ region(65) between the n+ source regions(67) and a part of the n+ source region(67). A junction portion between the n+ source region(67) and the p- well region(61) is overlapped with a junction portion between the p- well region(61) and the n- epitaxial layer(55).