Semiconductor device and method for manufacturing the same

A semiconductor device, comprising:

• a first semiconductor layer including Alx1Ga1-x1N (0≤x1<1), the first semiconductor layer including a first partial region, a second partial region, a third partial region, a fourth partial region, and a fifth partial region, a direction from the first partial region toward the second partial region being along a first direction, a position in the first direction of the third partial region being between a position in the first direction of the first partial region and a position in the first direction of the second partial region, a position in the first direction of the fourth partial region being between the position in the first direction of the first partial region and the position in the first direction of the third partial region, a position in the first direction of the fifth partial region being between the position in the first direction of the third partial region and the position in the first direction of the second partial region;
• a first electrode including a first electrode portion;
• a second electrode, a direction from the first electrode portion toward the second electrode being along the first direction;
• a third electrode, a position of the third electrode in the first direction being between a position of the first electrode portion in the first direction and a position of the second electrode in the first direction, a second direction from the third partial region toward the third electrode crossing the first direction;
• a second semiconductor layer including Alx2Ga1-x2N (0<x2≤1 and x1<x2), the second semiconductor layer including a first semiconductor portion and a second semiconductor portion, a direction from the fourth partial region toward the first semiconductor portion being along the second direction, a direction from the fifth partial region toward the second semiconductor portion being along the second direction;
• a third semiconductor layer including magnesium and Alx3Ga1-x3N (0<x3<1 and x1<x3), at least a portion of the first semiconductor layer being between the third semiconductor layer and the second semiconductor layer;
• and
• a first insulating member including a first insulating portion, the first insulating portion being provided between the third partial region and the third electrode.