Semiconductor device and method for manufacturing semiconductor device

A method for manufacturing a semiconductor device, comprising:

• joining a first semiconductor chip on a wiring layer arranged on an upper surface of an insulated circuit board;
• stacking a first sintered-metal layer by drying a metal sintering paste applied to an upper surface of the first semiconductor chip;
• arranging a first metal plate on the first sintered-metal layer so that the lower surface of the first metal plate is in contact with the first sintered-metal layer, the first metal plate having a plurality of first groove portions on a lower surface and a plurality of second groove portions on an upper surface;
• stacking a second sintered-metal layer by drying a metal sintering paste applied to the upper surface of the first metal plate;
• arranging a first wiring member on the second sintered-metal layer;
• and
• pressurizing and heating the first sintered-metal layer and the second sintered-metal layer, so that the first sintered-metal layer is joined to the lower surface of the first metal plate and the first semiconductor chip so that the first sintered-metal layer fills in the first groove portions, and the second sintered-metal layer is joined to the upper surface of the first metal plate and the first wiring member so that the second sintered-metal layer fills in the second groove portions.