Patent ID: 8823439

Claim:
A semiconductor device comprising: a first transistor comprising a first terminal, a second terminal, and a gate; a second transistor comprising a first terminal, a second terminal, and a gate, the first terminal electrically connected to the first terminal of the first transistor; a third transistor comprising a first terminal, a second terminal, and a gate, the first terminal electrically connected to the second terminal of the second transistor; a capacitor comprising a first terminal and a second terminal, the first terminal electrically connected to the second terminal of the second transistor and the first terminal of the third transistor; a fourth transistor comprising a first terminal, a second terminal, and a gate electrically connected to the first terminal of the first transistor and the first terminal of the second transistor; a first inverter comprising an input terminal and an output terminal, the input terminal electrically connected to the gate of the first transistor, the output terminal electrically connected to the gate of the second transistor; a second inverter comprising an input terminal and an output terminal, the output terminal electrically connected to the input terminal of the first inverter; a fifth transistor comprising a first terminal, a second terminal, and a gate, the second terminal electrically connected to the first terminal of the fourth transistor; and a plurality of transistors electrically connected in series, a gate and a first terminal of each of the plurality of transistors electrically connected to each other, one of the plurality of transistors comprising the gate electrically connected to the gate of the fifth transistor, wherein each of the first transistor, the second transistor, the third transistor, and the fourth transistor comprises an oxide semiconductor layer comprising indium, zinc, and a metal element other than indium and zinc, wherein each of the first transistor, the second transistor, and the third transistor is an re-channel type transistor, and wherein the fourth transistor is a depletion type transistor.