Semiconductor device

A semiconductor device comprising:

• a first element layer;
• a second element layer over the first element layer;
• and
• a third element layer over the second element layer,
• wherein the second element layer and the third element layer each comprises a temperature sensing circuit, a voltage generation circuit, and a memory cell,
• wherein the memory cell comprises a transistor in which a semiconductor layer comprising a channel formation region comprises an oxide semiconductor,
• wherein the transistor comprises a back gate,
• wherein the voltage generation circuit in the second element layer is configured to generate a back gate voltage supplied to the back gate of the transistor included in the memory cell in the second element layer, and
• wherein the temperature sensing circuit is configured to control the back gate voltage in accordance with a sensed temperature.

A semiconductor device comprising:

• a first element layer comprising a temperature sensing circuit and a voltage generation circuit;
• a second element layer over the first element layer;
• a third element layer over the second element layer;
• and
• a fourth element layer over the third element layer,
• wherein the second element layer comprises an amplifier circuit,
• wherein the third element layer and the fourth element layer each comprises a memory cell,
• wherein the amplifier circuit is configured to amplify a signal of the memory cell,
• wherein the amplifier circuit and the memory cell each comprise a transistor in which a semiconductor layer comprising a channel formation region comprises an oxide semiconductor,
• wherein the transistor comprises a back gate,
• wherein the voltage generation circuit is configured to generate a back gate voltage supplied to the back gate,
• wherein the temperature sensing circuit is configured to control the back gate voltage in accordance with a sensed temperature, and
• wherein the back gate voltage supplied to the third element layer and the back gate voltage supplied to the fourth element layer are different from each other.