US Patent 7411236 Semiconductor storage device

A semiconductor storage device has a first transistor of first conductive type which control data writing, a second transistor of second conductive type which controls data read-out, a third transistor which amplifies a current corresponding to data to be read out, a first semiconductor layer which is disposed in a predetermined direction, in which a gate of the first transistor is formed, a second semiconductor layer which is disposed separately from the first semiconductor layer in the predetermined direction, in which source and drain of the second transistor and source and drain of the third transistor are formed, a write transistor forming region which is disposed in a direction intersecting the first and second semiconductor layers, in which source and drain of the first transistor, a gate of the third transistor and an electric charge storing region storing electric charge in accordance with data to be written are formed, and a read-out transistor gate region which is disposed in a direction intersecting the first and second semiconductor layers, in which a gate of the second transistor is formed.