| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor device having nonvolatile memory cells which use an oxide semiconductor and includes a write transistor which has less leakage current (off-state current) between a source and a drain in an off state, a read transistor which uses a semiconductor material different from that of the write transistor and a capacitative element.SOLUTION: In a semiconductor device, writing of information into memory cells is performed by supplying potential to one of a source electrode and a drain electrode of a write transistor, and to one of electrodes of a capacitative element, and to a node to which a gate electrode of a read transistor is electrically connected to cause the node to retain a predetermined charge amount. Before as well as after performing writing 1×10times, an amount of change in memory window width of the memory cell is within 2%. |
