US Patent 10049728 Semiconductor memory device having bit cells

A semiconductor memory device including: a first transistor connected between a first node and ground, the first transistor having a gate connected to a second node; a second transistor connected between the second node and ground, the second transistor having a gate connected to the first node; a third transistor connected between first and third nodes, the third transistor having a gate connected to the second node; a fourth transistor connected between second and fourth nodes, the fourth transistor having a gate connected to the first node; a fifth transistor connected between the first node and bit line, the fifth transistor having a gate connected to a word line; a sixth transistor connected between the second node and complementary bit line, the sixth transistor having a gate connected to the word line; and a circuit to reduce a gate-source voltage of the third or fourth transistor in a write operation.