| 摘要 |
PROBLEM TO BE SOLVED: To improve saturation voltage to turn-off loss trade-off characteristics by constituting that a first conductivity drift layer appears on the main surface of a semiconductor substrate in the region in which the second conductivity well region is not formed. SOLUTION: Trenches 7 are formed with certain intervals on the main surface of one side of an n-type (a first conductive type) drift layer 1, a p-type (a second conductive type) well region 2 is selectively formed parallel to and in contact with this, and an (n) source region 3 is formed on a surface layer thereof. A part of the surface of the (n) source region 3 and the p-type (the second conductive type) well region 2 are removed and an insulating film 8 covers the main surface. Then, in the region in which the p-type (the second conductive type) well region 2 is not formed, the n-type (the first conductive type) drift layer 1 is allowed to reach the surface. In other words, a structure in which a part of the main surface is not covered with the p-type (the second conductive type) well region 2 is formed. The width of the n-type (the first conductive type) drift layer 1 should be about 80μm.
|
