Semiconductor memory device

1. A semiconductor memory device comprising:

a substrate;

a first stacked body comprising a plurality of first conductive layers stacked in a first direction intersecting with a surface of the substrate;

a second stacked body comprising a plurality of second conductive layers stacked in the first direction, and being adjacent to the first stacked body in a second direction intersecting with the first direction;

a plurality of semiconductor portions provided between the first stacked body and the second stacked body and arranged in a third direction intersecting with the first and second directions, the plurality of semiconductor portions comprising a first semiconductor layer facing the plurality of first conductive layers, a second semiconductor layer facing the plurality of second conductive layers, and a first insulating layer provided between the first semiconductor layer and the second semiconductor layer;

a first memory portion storing information between the first conductive layer and the first semiconductor layer;

a second memory portion storing information between the second conductive layer and the second semiconductor layer; and

a second insulating layer provided between the semiconductor portions adjacent to each other in the third direction,

wherein the width in the second direction of the first insulating layer has local maxima at a first position in the first direction and a second position in the first direction different from the first position,

wherein, referring to a cross-section which intersects with the first direction and on which a width in the second direction of at least one of the first insulating layers is the smallest in the range between the first and second positions as a first cross-section;

the smallest distance from a geometrical center of gravity of the second insulating layer to the first or second stacked body on the first cross-section being represented by D 1 ;

referring to a cross-section which intersects with the first direction and on which a width in the second direction of at least one of the first insulating layers is the largest as a second cross-section;

a distance from a surface of the first stacked body facing a predetermined one of the semiconductor portions to a surface of the second stacked body facing the predetermined one of the semiconductor portions on the second cross-section being represented by D 2 ,

a relationship 2D 1 >D 2 is satisfied.

2. The semiconductor memory device according to claim 1 wherein the width in the second direction of the first insulating layer has local maxima at a plurality of positions in the first direction,

among the plurality of positions at which the width in the second direction of the first insulating layer has local maxima, one of the plurality of the positions being closest to the substrate, is the first position, and one of the plurality of the positions being farthest from the substrate, is the second position.

3. The semiconductor memory device according to claim 1 wherein

the first insulating layer comprises a first insulating portion extending in the first direction, and a second insulating portion extending in the first direction farther from the substrate than the first insulating portion;

the second insulating layer comprises a third insulating portion extending in the first direction, and a fourth insulating portion extending in the first direction farther from the substrate than the third insulating portion; and

referring to a distance between a center position in the second direction of the first insulating portion and a center position in the second direction of the second insulating portion as d 1 , and

referring to a distance between the center position in the second direction of the second insulating portion and a center position in the second direction of the fourth insulating portion as d 2 ,

the relationship d 1 >d 2 is satisfied.

4. The semiconductor memory device according to claim 1 wherein

the first insulating layer comprises a first insulating portion extending in the first direction, and a second insulating portion extending in the first direction farther from the substrate than the first insulating portion;

the second insulating layer comprises a third insulating portion extending in the first direction, and a fourth insulating portion extending in the first direction farther from the substrate than the third insulating portion;

the first insulating portion is connected to the second insulating portion; and

the third insulating portion is connected to the fourth insulating portion.

5. The semiconductor memory device according to claim 1 wherein on the first cross-section, at least one of the first stacked body and the second stacked body comprises

a first surface facing the semiconductor portions, and

a second surface in contact with the second insulating layer,

wherein the first usrface and the second surface forms a continuous curved surface.

6. The semiconductor memory device according to claim 1 , comprising

a third insulating layer provided between the first stacked body and the first semiconductor layer, and containing the first memory portion, and

a fourth insulating layer provided between the second stacked body and the second semiconductor layer, and containing the second memory portion,

wherein the distance D 2 on the second cross-section is defined as a distance from an interface between the first stacked body and the third insulating layer to an interface between the second stacked body and the fourth insulating layer.

7. The semiconductor memory device according to claim 1 ,

wherein each of the semiconductor portions comprises a first portion extending in the first direction, a second portion extending in the first direction and being farther from the substrate than the first portion, and a connection portion connected to an end portion of an opposite side from the substrate of the first portion and an end portion of the substrate side of the second portion, a width in the second direction of the connection portion being larger than a largest width in the second direction of the first portion and the second portion,

wherein, referring to a width in the first direction of the connection portion as W 3 ,

the relationship D 2 >W 3 is satisfied.

8. The semiconductor memory device according to claim 1 ,

wherein the first memory portion is a first charge accumulation film, has an insulating property, is provided between the first stacked body and the first semiconductor layer, and

the second memory portion is a second charge accumulation film, having an insulating property, provided between the second stacked body and the second semiconductor layer.

9. The semiconductor memory device according to claim 1 ,

wherein the first memory portion is a first floating gate contained in the first stacked body, and

the second memory portion is a second floating gate contained in the second stacked body.

10. A semiconductor memory device comprising:

a substrate;

a first stacked body comprising a plurality of first conductive layers stacked in a first direction intersecting with a surface of the substrate;

a second stacked body comprising a plurality of second conductive layers stacked in the first direction, and being adjacent to the first stacked body in a second direction intersecting with the first direction;

a plurality of semiconductor portions provided between the first stacked body and the second stacked body and arranged in a third direction intersecting with the first and second directions, the plurality of semiconductor portions comprising a first semiconductor layer facing the plurality of first conductive layers, a second semiconductor layer facing the plurality of second conductive layers, and a first insulating layer provided between the first semiconductor layer and the second semiconductor layer;

a first memory portion storing information between the first conductive layer and the first semiconductor layer;

a second memory portion storing information between the second conductive layer and the second semiconductor layer; and

a second insulating layer provided between the semiconductor portions adjacent to each other in the third direction,

wherein the first insulating layer comprises a first insulating portion extending in the first direction, and a second insulating portion extending in the first direction farther from the substrate than the first insulating portion, and

the second insulating layer comprises a third insulating portion extending in the first direction, and a fourth insulating portion extending in the first direction farther from the substrate than the third insulating portion,

wherein, referring to a distance between a center position in the second direction of the first insulating portion and a center position in the second direction of the second insulating portion as d 1 ,

referring to a distance between the center position in the second direction of the second insulating portion and a center position in the second direction of the fourth insulating portion as d 2 ,

the relationship d 1 >d 2 is satisfied.

11. The semiconductor memory device according to claim 10 ,

wherein the first insulating portion is connected to the second insulating portion, and

the third insulating portion is connected to the fourth insulating portion.

12. The semiconductor memory device according to claim 10 ,

wherein the first memory portion is a first charge accumulation film, has an insulating property, is provided between the first stacked body and the first semiconductor layer, and

the second memory portion is a second charge accumulation film, has an insulating property, is provided between the second stacked body and the second semiconductor layer.

13. The semiconductor memory device according to claim 10 ,

wherein the first memory portion is a first floating gate contained in the first stacked body, and

the second memory portion is a second floating gate contained in the second stacked body.