SEMICONDUCTOR DEVICE AND SEMICONDUCTOR DEVICE MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a normally-off semiconductor device which can be manufactured with good yield.SOLUTION: A semiconductor device comprises: a first semiconductor layer 24; a second semiconductor layer 26 which is formed on the first semiconductor layer 24 and forms hetero junction with the first semiconductor layer 24; a third semiconductor layer 28 of n-type or i-type formed on the second semiconductor layer 26; an n-type fourth semiconductor layer 30 which is formed on the third semiconductor layer 28 and has an n-type impurity concentration higher than that of the third semiconductor layer 28; and a gate electrode 64 which is formed in a recess 60 piercing the fourth semiconductor layer 30 to reach the third semiconductor layer 28 and which is insulated from the third semiconductor layer 28 and the fourth semiconductor layer 30 by a gate insulation film 62.