| 摘要 |
PURPOSE:To prevent an occurrence of a leakage current on a p-n junction by making the p-n junction with an impurity density of both p- and n-type sides or just one side at low. CONSTITUTION:A thin insulating film 7 is formed on a trench side wall. High- density impurity layers 2 and 3 are formed on a substrate side, being in contact with the insulating film 7. At the time, a p-n junction of the impurity layers 2 and 3 is made in low density on both sides 4 and 5 of the p-n junction or on one side near a place where the p-n junction is terminated and is brought into contact with the insulating film 7. At the same time, the insulating film is formed thicker other place where the p-n junction of the high-density impurity layers 2 and 3 formed on the substrate side, being in contact with the trench side wall, is terminated and is brought into contact with the trench side wall. |
