A semiconductor device includes a metal layer disposed above a transistor on a first substrate. The metal layer includes a first region extending in a first direction and a second region that has a width in the first direction smaller than the first region and protrudes from the first region in a second direction, and has a first corner portion having an angle larger than 180° as viewed in a third direction between a proximal end portion of the second region and the first region. The metal layer includes a first portion that is disposed within the first region and has a lower surface at a first height, and a second portion that is disposed within the second region and has a lower surface at a second height lower than the first height. A step present at a boundary between the first portion and the second portion is disposed away from an edge of the second region at a first position near the first corner portion in the second direction and adjacent to the edge of the second region at a second position away from the first corner portion than the first position.