US Patent 11251193 Semiconductor memory device

A semiconductor memory device includes a substrate, gate electrodes arranged in a thickness direction of the substrate, first and second semiconductor layers, a gate insulating film, and a first contact. The first semiconductor layer extends in the thickness direction and faces the gate electrodes. The gate insulating film is between the gate electrodes and the first semiconductor layer. The second semiconductor layer is between the substrate and the gate electrodes and connected to a side surface of the first semiconductor layer in a surface direction. The first contact extends in the thickness direction and electrically connected to the second semiconductor layer. The second semiconductor layer includes a first region in contact with the side surface of the first semiconductor layer and containing P-type impurities, and a first contact region electrically connected to the first contact and having a higher concentration of N-type impurities than the first region.