| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent field concentration on a trench gate end at the time of a recovery operation thereby to inhibit breakdown of a gate insulation film.SOLUTION: A semiconductor device comprises a p-type deep layer 18 which contacts a p-type high impurity layer 10 and is formed so as to cover at least a tip of each trench 7 protruding to an outer edge of a surface electrode 12, in which a p-type impurity concentration of the p-type deep layer 18 is set higher than that of a p-type layer 5. This makes the p-type deep layer 18 have source potential substantially the same with the surface electrode 12 via the p-type high impurity layer 10 when injected careers are drawn out at the time of a recovery operation. For this reason, an equipotential line can be made to extend along the p-type deep layer 18. Accordingly, field concentration can be relaxed by reducing potential applied to the inside a gate insulation film 8 at a tip of a trench gate which is covered with the p-type deep layer 18 and breakdown of the gate insulation film 8 can be inhibited.</p> |
