| 摘要 |
PROBLEM TO BE SOLVED: To reduce standby power and prevent malfunction of a logic circuit performing clock gating.SOLUTION: A logic circuit has a transistor that turns off in a state in which a potential difference exists between a source terminal and a drain terminal over a period in which a clock signal is not supplied. A channel formation region of the transistor is composed of an oxide semiconductor in which a hydrogen concentration is reduced. Specifically, the hydrogen concentration of the oxide semiconductor is 5×10(atoms/cm) or less. For this reason, a leakage current of the transistor can be reduced. Consequently, the standby power of the logic circuit can be reduced, and the malfunction of the logic circuit can be prevented. |
