Semiconductor device and method of manufacturing the same

A semiconductor device comprising:

• a first semiconductor layer including a first substrate and a first circuit disposed on the first substrate, the first circuit comprising at least one transistor having a gate insulation layer of a first thickness;
• an insulating layer disposed on the first semiconductor layer;
• a second semiconductor layer disposed on the insulating layer, the second semiconductor layer including a second substrate and a second circuit disposed on the second substrate, the second circuit comprising at least one transistor having a gate insulation layer of a second thickness different from the first thickness;
• and
• a via in the second semiconductor layer and the insulating layer, the via electrically connecting the first circuit and the second circuit,
• wherein one of the first and second circuits comprises a logic circuit and the other of the first and second circuits comprises a memory circuit.

A semiconductor device comprising:

• a first semiconductor substrate;
• a logic circuit disposed on the first semiconductor substrate, the logic circuit comprising a first transistor having a first gate insulation layer of a first thickness and a first insulation layer covering the first transistor;
• a second semiconductor substrate disposed on the first semiconductor substrate;
• a memory circuit disposed on the second semiconductor substrate, the memory circuit comprising a second transistor having a second gate insulation layer of a second thickness different from the first thickness, a bit line electrically connected to the second transistor, and insulation covering the second transistor;
• and
• a via extending through the first insulation layer and the second semiconductor substrate and electrically connecting the logic circuit and the memory circuit.