SEMICONDUCTOR MEMORY DEVICE AND DRIVING METHOD THEREOF

摘要

PURPOSE: A semiconductor memory device and a driving method thereof are provided to implement the semiconductor memory device without refresh by using a sub bit line with small capacity and deceasing capacity of a capacitive device. CONSTITUTION: A plurality of cells are connected to one main bit line(MBL_m). Each cell has a sub bit line(SBL_n_m) and 2 to 32 memory cells. Each cell includes a selection transistor(STr_n_m) and a reading transistor(RTr_n_m). The sub bit line is connected to a gate of the reading transistor. Charge information of a capacitive device of each memory cell is amplified in the reading transistor without an error and is outputted to a main bit line because a parasitic capacity of the sub bit line is enough small.