Semiconductor device

A semiconductor device which is a chip-size-package-type semiconductor device that is facedown mountable, the semiconductor device comprising:

• a semiconductor layer that includes a first principal surface and a second principal surface that face in opposite directions, and comprises silicon, gallium nitride, or silicon carbide;
• a first metal layer that includes a third principal surface and a fourth principal surface that face in opposite directions, is disposed with the third principal surface in contact with the second principal surface, is thicker than the semiconductor layer, and comprises a first metal material;
• a second metal layer that includes a fifth principal surface and a sixth principal surface that face in opposite directions, and comprises a second metal material having a Young's modulus greater than a Young's modulus of the first metal material;
• a first vertical field effect transistor disposed in a first region of the semiconductor layer;
• and
• a second vertical field effect transistor disposed in a second region adjacent to the first region in a direction along the first principal surface in the semiconductor layer,
• wherein the first vertical field effect transistor includes a first source electrode and a first gate electrode on a side facing the first principal surface of the semiconductor layer,
• the second vertical field effect transistor includes a second source electrode and a second gate electrode on the side facing the first principal surface of the semiconductor layer,
• the first metal layer functions as a common drain electrode for the first vertical field effect transistor and the second vertical field effect transistor, and
• a bidirectional path from the first source electrode to the second source electrode via the common drain electrode is a primary current path.