Patent ID: 9196345
Filing Date: 2015-11-24
Classification: G11C

Abstract:
1. A driving method of a semiconductor device including a first word line, a second word line, a first bit line, a second bit line, a first wiring, a first transistor, a second transistor, and a third transistor between the second transistor and the second bit line or between the second transistor and the first wiring, wherein a gate of the first transistor is electrically connected to the first word line, one of a source and a drain of the first transistor is electrically connected to the first bit line, and the other of the source and the drain of the first transistor is electrically connected to a gate of the second transistor, wherein one of a source and a drain of the second transistor is electrically connected to the first wiring to which a potential V1 is supplied, and the other of the source and the drain of the second transistor is electrically connected to the second bit line, and wherein a gate of the third transistor is connected to the second word line, the method comprising the steps of: setting a potential of the first bit line to a potential VH or a potential VL that is lower than VH and turning on the first transistor; turning off the first transistor; and bringing the second bit line into a floating state at a potential V2, and then turning on the third transistor, wherein V2<V1<V3−Vth is satisfied where: Vth is a threshold value of the second transistor; and V3 is a potential of the gate of the second transistor after a retention period when the potential of the first bit line is set to VH, and wherein the retention period is a period between the step of turning off the first transistor and the step of bringing the second bit line into the floating state.