US Patent 7859889 Semiconductor memory device

In a two-transistor gain cell structure, a semiconductor memory device capable of stable reading without malfunction and having small-area memory cells is provided. In a two-transistor gain cell memory having a write transistor and a read transistor, a write word line, a read word line, a write bit line, and a read bit line are separately provided, and voltages to be applied are independently set. Furthermore, a memory cell is connected to the same read word line and write bit line as those of an adjacent memory cell.