US Patent 9384815 Mechanisms for preventing leakage currents in memory cells

Memory cells and operation methods thereof are provided. A memory device includes a number of memory cells. Each of the memory cells includes a first transistor, a switch and a capacitor. The first transistor has a drain connected to a corresponding bit-line. The switch has a first terminal connected to a source of the first transistor and a second terminal coupled to a reference voltage. The capacitor has a first plate and a second plate, and the first plate of the capacitor is electrically connected to a gate of the first transistor. The second plate of the capacitor is connected to a corresponding word line. The switch is turned off when the memory cell is not selected to perform a write operation or a read operation.