Semiconductor device

A semiconductor device comprising:

• a first semiconductor substrate and a second semiconductor substrate laminated with an insulating layer interposed between the first semiconductor substrate and the second semiconductor substrate;
• a first transmission line formed on said first semiconductor substrate, the first transmission line including a signal line and a ground;
• a second transmission line formed on said second semiconductor substrate, the second transmission line including a signal line and a ground;
• a first via layer for the signal lines, the first via layer for the signal lines being formed of a conductor layer formed within a via hole, and connected to the signal line of said first transmission line and the signal line of said second transmission line;
• a first via layer for the grounds, the first via layer for the grounds being formed of a conductor layer formed within a via hole, and connected to the ground of said first transmission line and the ground of said second transmission line;
• and
• a second via layer for the grounds, the second via layer for the grounds being formed of a conductor layer formed within a via hole, connected to the ground of said first transmission line and/or the ground of said second transmission line, and including a via layer in a shape of a band, the via layer in the shape of the band being formed so as to be opposed to said first via layer for the signal lines.