Semiconductor device

A semiconductor device, comprising:

• a semiconductor body including a first semiconductor layer of a first conductivity type;
• a first electrode provided on a front surface of the semiconductor body;
• a first control electrode placed inside a first trench, the first trench being provided on the front surface side of the semiconductor body, the first control electrode being electrically insulated from the semiconductor body by a first insulating film;
• a second control electrode placed inside a second trench adjacent to the first trench on the front surface side of the semiconductor body, the second control electrode being electrically insulated from the semiconductor body by a second insulating film;
• and
• a second electrode provided on the front surface of the semiconductor body with a third insulating film interposed, the second electrode being electrically connected to the first control electrode and the second control electrode,
• the second electrode being placed to be spaced from the first electrode,
• the first control electrode and the second control electrode each including a first portion, a second portion, and a third portion, the first portion being positioned between the semiconductor body and the first electrode, the second portion being positioned between the semiconductor body and the second electrode, the third portion being linked to the first portion and the second portion,
• the semiconductor body further including a second semiconductor layer of a second conductivity type, a third semiconductor layer of the first conductivity type, and a fourth semiconductor layer of the second conductivity type, the second to fourth semiconductor layers being provided between the first control electrode and the second control electrode,
• the second semiconductor layer being provided on the first semiconductor layer and extending along the first portions, the third portions, and the second portions of the first control electrode and the second control electrode,
• the third semiconductor layer being selectively provided between the second semiconductor layer and the first electrode,
• the fourth semiconductor layer being provided selectively on the second semiconductor layer, the fourth semiconductor layer extending along the third portions and the second portions of the first control electrode and the second control electrode along an extension direction of the first control electrode and the second control electrode, the fourth semiconductor layer including second conductivity-type impurities with a higher concentration than a concentration of second conductivity-type impurities in the second semiconductor layer.