Nonvolatile semiconductor memory device and manufacturing method thereof
A nonvolatile semiconductor memory device that have a new structure are provided, in which memory cells are laminated in a three dimensional state so that the chip area may be reduced. The nonvolatile semiconductor memory device of the present invention is a nonvolatile semiconductor memory device that has a plurality of the memory strings, in which a plurality of electrically programmable memory cells is connected in series. The memory strings comprise a pillar shaped semiconductor; a first insulation film formed around the pillar shaped semiconductor; a charge storage layer formed around the first insulation film; the second insulation film formed around the charge storage layer; and first or nth electrodes formed around the second insulation film (n is natural number more than 1). The first or nth electrodes of the memory strings and the other first or nth electrodes of the memory strings are respectively the first or nth conductor layers that are spread in a two dimensional state.
1. A nonvolatile semiconductor memory device comprising:
an n type semiconductor area;
a plurality of electrode layers stacked in a first direction and provided above the n type semiconductor area, the plurality of electrode layers including a first electrode layer;
a first semiconductor layer penetrating through the plurality of electrode layers and contacting the n type semiconductor area;
a first charge storage portion provided between the first semiconductor layer and the first electrode layer;
a second semiconductor layer penetrating through the plurality of electrode layers and contacting the n type semiconductor area, the first semiconductor layer and the second semiconductor layer being arranged in a second direction perpendicular to the first direction;
a second charge storage portion provided between the second semiconductor layer and the first electrode layer;
a third semiconductor layer penetrating through the plurality of electrode layers and contacting the n type semiconductor area, the first semiconductor layer and the third semiconductor layer being arranged in a third direction, the third direction being perpendicular to the first direction and different from the second direction; and
a third charge storage portion provided between the third semiconductor layer and the first electrode layer.
2. The nonvolatile semiconductor memory device according to claim 1 , wherein
the n type semiconductor area includes materials giving the N type in a semiconductor area.
3. The nonvolatile semiconductor memory device according to claim 2 , wherein
the n type semiconductor area includes phosphorous.
4. The nonvolatile semiconductor memory device according to claim 3 , wherein
the n type semiconductor area is provided on a first material thicker than the n type semiconductor area.
5. The nonvolatile semiconductor memory device according to claim 4 , wherein
the first material is a p type semiconductor layer.
6. The nonvolatile semiconductor memory device according to claim 1 , the device further comprising:
a second electrode layer provided above the plurality of electrode layers in the first direction; and
a third electrode layer provided above the plurality of electrode layers in the first direction, the second electrode layer and the third electrode layer being arranged in the second direction and isolated from each other.
7. The nonvolatile semiconductor memory device according to claim 1 , further comprising:
a first bit line extending in the second direction and electrically connected to the first semiconductor layer and the second semiconductor layer; and
a second bit line extending in the second direction and electrically connected to the third semiconductor layer.
8. The nonvolatile semiconductor memory device according to claim 6 , further comprising:
a first gate insulating portion provided between the first semiconductor layer and the second electrode layer;
a second gate insulating portion provided between the second semiconductor layer and the third electrode layer; and
a third gate insulating portion provided between the third semiconductor layer and the second electrode layer.
9. The nonvolatile semiconductor memory device according to claim 8 , wherein
the first electrode layer is a gate of a first memory cell transistor having the first semiconductor layer and the first charge storage portion, a gate of a second memory cell transistor having the second semiconductor layer and the second charge storage portion, and a gate of a third memory cell transistor having the third semiconductor layer and the third charge storage portion,
the second electrode layer is a gate of a first select transistor having the first semiconductor layer and the first gate insulating portion, and a gate of a third select transistor having the third semiconductor layer and the third gate insulating portion, and
the third electrode layer is a gate of a second select transistor having the second semiconductor layer and the second gate insulating portion.
10. The nonvolatile semiconductor memory device according to claim 6 , wherein
the plurality of electrode layers include a fourth electrode layer above the first electrode layer in the first direction.
11. The nonvolatile semiconductor memory device according to claim 10 , further comprising:
a fourth charge storage portion provided between the first semiconductor layer and the fourth electrode layer;
a fifth charge storage portion provided between the second semiconductor layer and the fourth electrode layer; and
a sixth charge storage portion provided between the third semiconductor layer and the fourth electrode layer.
12. The nonvolatile semiconductor memory device according to claim 1 , further comprising:
a fifth electrode layer below the plurality of electrode layers in the first direction; and
a sixth electrode layer below the plurality of electrode layers in the first direction, the fifth electrode layer and the sixth electrode layer being arranged in the second direction and isolated from each other.
13. The nonvolatile semiconductor memory device according to claim 12 , further comprising:
a fourth gate insulating portion provided between the first semiconductor layer and the fifth electrode layer;
a fifth gate insulating portion provided between the second semiconductor layer and the sixth electrode layer; and
a sixth gate insulating portion provided between the third semiconductor layer and the fifth electrode layer.
14. The nonvolatile semiconductor memory device according to claim 13 , wherein
the fifth electrode layer is a gate of a fourth select transistor having the first semiconductor layer and the fourth gate insulating portion, and a gate of a sixth select transistor having the third semiconductor layer and the sixth gate insulating portion, and
the sixth electrode layer is a gate of a fifth select transistor having the second semiconductor layer and the fifth gate insulating portion.
15. The nonvolatile semiconductor memory device according to claim 9 , further comprising:
a fifth electrode layer below the plurality of electrode layers in the first direction;
a sixth electrode layer below the plurality of electrode layers in the first direction, the fifth electrode layer and the sixth electrode layer being arranged in the second direction and isolated from each other;
a fourth gate insulating portion provided between the first semiconductor layer and the fifth electrode layer;
a fifth gate insulating portion provided between the second semiconductor layer and the sixth electrode layer; and
a sixth gate insulating portion provided between the third semiconductor layer and the fifth electrode layer,
wherein
the fifth electrode layer is a gate of a fourth select transistor having the first semiconductor layer and the fourth gate insulating portion, and a gate of a sixth select transistor having the third semiconductor layer and the sixth gate insulating portion, and
the sixth electrode layer is a gate of a fifth select transistor having the second semiconductor layer and the fifth gate insulating portion.