SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURING THE SAME

To provide a semiconductor device capable of suppressing variation in gate threshold voltage, in a structure with a contact trench.SOLUTION: A semiconductor device comprises: a semiconductor substrate 10 of a first conductivity type; an insulated gate electrode structure (6, 7) buried in a first trench 11 provided on the semiconductor substrate 10; a base region 3 of a second conductivity type provided on the semiconductor substrate 10 so as to be in contact with the first trench 11; a first main electrode region 4a, 4b of the first conductivity type provided above the base region 3 so as to be in contact with the first trench 11; a polysilicon film 15 of the second conductivity type buried in a second trench 14 provided on the semiconductor substrate 10, being in contact with the base region 3 and having a higher impurity concentration than the base region 3; and a second main electrode region 9 provided at a lower surface side of the semiconductor substrate 10.SELECTED DRAWING: Figure 2 【課題】コンタクトトレンチを有する構造において、ゲート閾値電圧のばらつきを抑制することができる半導体装置を提供する。【解決手段】第１導電型の半導体基板１０と、半導体基板１０に設けられた第１トレンチ１１に埋め込まれた絶縁ゲート型電極構造（６，７）と、半導体基板１０に第１トレンチ１１に接して設けられた第２導電型のベース領域３と、ベース領域３の上部に第１トレンチ１１に接して設けられた第１導電型の第１主電極領域４ａ，４ｂと、半導体基板１０に設けられた第２トレンチ１４に埋め込まれ、ベース領域３に接し、ベース領域３よりも高不純物濃度の第２導電型のポリシリコン膜１５と、半導体基板１０の下面側に設けられた第２主電極領域９を備える。【選択図】図２