| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a semiconductor device which can suppress variations in the thickness of an impurity layer formed in a trench, and also a method for manufacturing the semiconductor device. <P>SOLUTION: A dummy trench 12 is formed so as to surround the outer periphery of a trench 2 in which a power MOSFET is formed, and an n-type drift region 3, a p-type base region 4, and an n<SP>+</SP>-type source region 5 are also formed in the dummy trench 12. Consequently, even if variations take place in the thicknesses of the n-type drift region 3, the p-type base region 4, and the n<SP>+</SP>-type source region 5 formed in the dummy trench 12; such thickness variations can be minimized or eliminated in the trench 2 wherein the power MOSFET is formed. <P>COPYRIGHT: (C)2007,JPO&INPIT |
