Semiconductor device and semiconductor device manufacturing method

A semiconductor device comprising:

• a first semiconductor layer including a first region and a second region;
• an insulator layer provided above the first semiconductor layer;
• a second semiconductor layer provided above the first region of the first semiconductor layer and above the insulator layer;
• a p-type conduction region provided under the second semiconductor layer;
• a second element formed in the second region of the first semiconductor layer;
• a first electrode connected to the p-type conduction region;
• a second electrode connected to the second semiconductor layer;
• a third electrode connected to the first electrode and the second region;
• and
• a first element formed in the second semiconductor layer,
• wherein the p-type conduction region has a thickness such that a first inversion layer formed at an insulator layer side of the p-type conduction region and a second inversion layer formed at a second semiconductor layer side of the p-type conduction region do not contact each other.