US Patent 8704221 Semiconductor device

A semiconductor device with high productivity and high yield is provided. The semiconductor device includes a word line, a capacitor line, a first bit line, a second bit line, and a first transistor and a second transistor each of which includes a gate, a source, and a drain. The first transistor and the second transistor at least partly overlap with each other, and the gates of the first transistor and the second transistor are connected to the word line. A capacitor is formed between at least part of the capacitor line and each of the drains of the first transistor and the second transistor. The first bit line is connected to the source of the first transistor, and the second bit line is connected to the source of the second transistor.