| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor device in which a memory composed of an oxide semiconductor of quite-small leakage current is added to a flip flop and used and which can temporarily hold data without significantly changing electrical characteristic of a transistor including the oxide semiconductor of quite-small leakage current in a channel region.SOLUTION: In a semiconductor device, a channel length of a transistor including an oxide semiconductor in a channel region is made larger than a channel length of a transistor including silicon in a channel region thereby to inhibit shift of a threshold voltage to a negative side more than a case where the channel lengths are the same. In particular, when assuming that a channel length of the transistor including silicon in the channel region is Ls and a channel length of the transistor including the oxide semiconductor in the channel region is Lo, a ratio Ls/Lo is not less than 1/200 and not more than 1/6. |
