Semiconductor memory

Abstract

A semiconductor memory according to an embodiment includes a first conductor, a first insulator and memory pillars. The first conductor and the first insulator are alternately stacked along a first direction. The memory pillars penetrates through the stacked first conductor and first insulator. Each of the memory pillars include a semiconductor, a tunnel insulating film, a second insulator, and a block insulating film. The memory pillars include a first memory pillar. The stacked first insulator includes a first layer and a second layer that are adjacent to each other in the first direction. The first conductor between the first layer and the second layer includes a first conductive part, a second conductive part, and a first dissimilar conductive part.

What is claimed is: 
     
         1 . A semiconductor memory comprising:
 a first conductor and a first insulator that are alternately stacked along a first direction; and   a plurality of memory pillars that penetrates through the stacked first conductor and first insulator, each of the memory pillars including a semiconductor along the first direction, a tunnel insulating film that surrounds a side surface of the semiconductor, a second insulator that surrounds a side surface of the tunnel insulating film, and a block insulating film that surrounds a side surface of the second insulator, wherein   the memory pillars include a first memory pillar,   the stacked first insulator includes a first layer and a second layer that are adjacent to each other in the first direction,   the first conductor between the first layer and the second layer includes a first conductive part and a second conductive part, the first conductive part is in contact with the first layer and the second layer and widens along a second direction crossing the first direction, the second conductive part is provided between a block insulating film of the first memory pillar and the first conductive part, is in contact with the block insulating film and the first conductive part, and is formed from the same material as for the first conductive part, and   a portion between the block insulating film of the first memory pillar and the first conductive part includes a space.   
     
     
         2 . The memory of  claim 1 , wherein
 the memory pillars further include a second memory pillar adjacent to the first memory pillar, and   in a cross section parallel to a surface of a substrate and including the space, a first distance between a center of the first memory pillar and a portion of the space most distant from the first memory pillar is shorter than half a second distance between the center of the first memory pillar and a center of the second memory pillar.   
     
     
         3 . The memory of  claim 1 , wherein
 the memory pillars further include a second memory pillar adjacent to the first memory pillar,   the first conductor between the first layer and the second layer further includes a third conductive part,   the third conductive part is provided between a block insulating film of the second memory pillar and the first conductive part, is in constant with the block insulating film of the second memory pillar and the first conductive part, and is formed from the same material as for the first conductive part, and   the first conductive part includes a seam along the first direction between the first memory pillar and the second memory pillar.   
     
     
         4 . The memory of  claim 1 , further comprising:
 an insulation part that is provided in a slit extending along a third direction crossing the first direction and dividing the stacked first conductor and first insulator, and is in contact with the first conductive part, wherein   no memory pillar is included between the first memory pillar and the insulation part, and   no seam is included in the first conductive part between the first memory pillar and the insulation part.   
     
     
         5 . The memory of  claim 1 , wherein
 a boundary is formed between the first conductive part and the second conductive part.   
     
     
         6 . The memory of  claim 1 , wherein
 the block insulating film of the first memory pillar includes a portion sandwiched between the first layer and the second layer.   
     
     
         7 . The memory of  claim 1 , wherein
 the block insulating film includes a cylinder-shaped first oxide along the first direction and a second oxide different from the first oxide along the first direction, and   the second oxide surrounds a side surface of the first oxide.   
     
     
         8 . The memory of  claim 1 , wherein
 the second conductive part is provided in a single-annular form.   
     
     
         9 . The memory of  claim 1 , wherein
 each of the first conductive part and the second conductive part includes tungsten.