Nonvolatile semiconductor memory device
View Patent ↗According to one embodiment, in a nonvolatile semiconductor memory device, a first line is disposed on a semiconductor substrate. A first memory cell is disposed on a side opposite to the semiconductor substrate with respect to the first line. A second line intersects with the first line via the first memory cell. A second memory cell is disposed on a side opposite to the semiconductor substrate with respect to the second line. A third line intersects with the second line via the second memory cell. The first memory cell has a first resistance change layer and a first rectification layer. The second memory cell has a second resistance change layer and a second rectification layer. A composition of the first resistance change layer is different from a composition of the second resistance change layer.
1. A nonvolatile semiconductor memory device comprising:
a semiconductor substrate;
a first line disposed above the semiconductor substrate;
a first memory cell disposed on a side opposite to the semiconductor substrate with respect to the first line;
a second line intersecting with the first line via the first memory cell;
a second memory cell disposed on a side opposite to the semiconductor substrate with respect to the second line; and
a third line intersecting with the second line via the second memory cell, wherein the first memory cell has a first resistance change layer and a first rectification layer,
the second memory cell has a second resistance change layer and a second rectification layer, and
a composition of the first resistance change layer is different from a composition of the second resistance change layer, wherein
the first resistance change layer is formed of a first carbon-based material, and the second resistance change layer is formed of a metal oxide.
2. The nonvolatile semiconductor memory device according to claim 1 , wherein
the first carbon-based material comprises a material containing SiC as a main component or a material containing a carbon nanotube as a main component, and
the metal oxide comprises a material containing, as a main component, at least one selected from a group consisting of ZnMn 2 O 4 , NiO, HfO, TiO 2 , SrZrO 3 , and Pr 0.7 Ca 0.3 MnO 3 .
3. The nonvolatile semiconductor memory device according to claim 1 , further comprising:
a third memory cell disposed between the semiconductor substrate and the first line; and
a fourth line disposed between the semiconductor substrate and the third memory cell, the fourth line intersecting with the first line via the third memory cell, wherein
the third memory cell has a third resistance change layer and a third rectification layer, and
wherein
the third resistance change layer is formed from a second carbon-based material.
4. The nonvolatile semiconductor memory device according to claim 3 , wherein
the second carbon-based material comprises a material containing a carbon nanotube as a main component,
the first carbon-based material comprises a material containing SiC as a main component, and
the metal oxide comprises a material containing, as a main component, at least one selected from the group consisting of ZnMn 2 O 4 , NiO, HfO, TiO 2 , SrZrO 3 , and Pr 0.7 Ca 0.3 MnO 3 .
5. A nonvolatile semiconductor memory device comprising:
a semiconductor substrate;
a first line disposed on the semiconductor substrate;
a first memory cell disposed on a side opposite to the semiconductor substrate with respect to the first line;
a second line intersecting with the first line via the first memory cell;
a second memory cell disposed on a side opposite to the semiconductor substrate with respect to the second line; and
a third line intersecting with the second line via the second memory cell, wherein
the first memory cell has a first resistance change layer and a first rectification layer,
the second memory cell has a second resistance change layer and a second rectification layer, and
a film thickness of the first resistance change layer is larger than a film thickness of the second resistance change layer.
6. The nonvolatile semiconductor memory device according to claim 5 , further comprising:
a third memory cell disposed on a side opposite to the semiconductor substrate with respect to the third line; and
a fourth line intersecting with the third line via the third memory cell, wherein
the third memory cell has a third resistance change layer and a third rectification layer, and
a film thickness of the second resistance change layer is larger than a film thickness of the third resistance change layer.
7. A nonvolatile semiconductor memory device comprising:
a semiconductor substrate;
a first line disposed on the semiconductor substrate;
a first memory cell disposed on a side opposite to the semiconductor substrate with respect to the first line;
a second line intersecting with the first line via the first memory cell;
a third line disposed on a side opposite to the semiconductor substrate with respect to the second line;
a second memory cell disposed on a side opposite to the semiconductor substrate with respect to the third line;
a fourth line intersecting with the third line via the second memory cell; and
an insulation film insulating the second line and the third line from each other, wherein
the first memory cell has a first resistance change layer and a first rectification layer,
the second memory cell has a second resistance change layer and a second rectification layer,
a width of the first resistance change layer in a planar direction which is parallel to a surface of the semiconductor substrate is larger than a width of the second resistance change layer in a planar direction which is parallel to the surface of the semiconductor substrate, and
a width of each of the first line and the second line is larger than a width of each of the third line and the fourth line.
8. The nonvolatile semiconductor memory device according to claim 7 , further comprising:
a fifth line disposed adjacent to the third line via an interlayer insulation film on a side opposite to the semiconductor substrate with respect to the second line;
a third memory cell disposed adjacent to the second memory cell via the interlayer insulation film on a side reverse to the semiconductor substrate with respect to the fifth line; and
a sixth line intersecting with the fifth line via the third memory cell, wherein
a width of each of the first line and the second line is equivalent to a sum of the width of each of the third line and the fourth line, a width of each of the fifth line and the sixth line, and a space between the third line and the fifth line.
9. The nonvolatile semiconductor memory device according to claim 8 , wherein
the third memory cell has a third resistance change layer and a third rectification layer; and
a width of the second resistance change layer in a planar direction which is parallel to the surface of the semiconductor substrate is equivalent to a width of the third resistance change layer in a planar direction which is parallel to the surface of the semiconductor substrate.
10. The nonvolatile semiconductor memory device according to claim 7 , wherein
a film thickness of the first resistance change layer is larger than a film thickness of the second resistance change layer.
11. The nonvolatile semiconductor memory device according to claim 10 , wherein
a composition of the first resistance change layer is different from a composition of the second resistance change layer.