Semiconductor memory device

1. A semiconductor memory device comprising:

a plurality of first interconnect layers extending in a first direction that is substantially parallel to a semiconductor substrate;

a plurality of second interconnect layers extending in the first direction, and being separate from and adjacent to the first interconnect layers in a second direction that is substantially parallel to the semiconductor substrate and orthogonal to the first direction;

a first memory pillar extending through the first interconnect layers in a third direction that is substantially vertical to the semiconductor substrate;

a second memory pillar extending through the second interconnect layers in the third direction;

a first film above the first interconnect layers, the first film having a planar shape corresponding to the first interconnect layers and extending in the first direction;

a second film above the second interconnect layers, the second film being separate from the first film in the second direction, having a planar shape corresponding to the second interconnect layers and extending in the first direction; and

a third film extending in the first direction between the first interconnect layers and the second interconnect layers, and having a compressive stress higher than a silicon oxide film,

wherein the first and second films have a compressive stress higher than a silicon oxide film.

2. The device according to claim 1 , wherein:

the first and second films include one of amorphous silicon, polysilicon, silicon nitride formed by physical vapor deposition (PVD), and nitrogen-containing tungsten, and

the third film includes one of amorphous silicon, polysilicon, and silicon nitride formed by PVD.

3. The device according to claim 1 , further comprising:

a first contact plug on the first memory pillar, the first contact plug extending through the first film in the third direction.

4. The device according to claim 3 , further comprising:

a third insulating layer between the first film and the first contact plug.

5. The device according to claim 1 , wherein:

the third film is further provided between the first film and the second film.

6. The device according to claim 1 , wherein:

the third film includes nitrogen-containing tungsten.

7. The device according to claim 6 , wherein:

the third film is electrically coupled to a diffusion layer formed in the semiconductor substrate.

8. The device according to claim 6 , further comprising:

a fourth insulating layer between the third film and the first interconnect layers; and

a fifth insulating layer between the third film and the second interconnect layers.

9. The device according to claim 6 , wherein:

a thickness of the third film in a portion near a top of the third film is smaller than a thickness of the third film in a portion near a bottom of the third film.

10. The device according to claim 9 , further comprising:

a second conductive layer having a side surface and a bottom surface that are in contact with the third film, and extending in the first direction.

11. The device according to claim 10 , wherein:

the second conductive layer includes tungsten having a smaller content of nitrogen than a content of nitrogen in the nitrogen-containing tungsten of the third film.

12. The device according to claim 11 , wherein:

the second conductive layer further includes a barrier metal having a side surface and a bottom surface that are in contact with the third film, and the side surface and bottom surface of the tungsten having the smaller content of nitrogen are in contact with the barrier metal.

13. The device according to claim 1 , further comprising:

a sixth insulating layer extending in the first direction and being in contact with two side surfaces of the third film facing the second direction and the bottom surface of the third film.

14. The device according to claim 1 , wherein:

the first and second films have a compressive stress of an absolute value of 300 MPa or greater.

15. The device according to claim 1 , wherein:

the first film is provided above the first memory pillar, and

the second film is provided above the second memory pillar.

16. The device according to claim 1 , wherein:

each of the first and second memory pillars includes a charge storage layer and a semiconductor layer.

17. A semiconductor memory device comprising:

a plurality of first interconnect layers extending in a first direction that is substantially parallel to a semiconductor substrate;

a plurality of second interconnect layers extending in the first direction, and being separate from and adjacent to the first interconnect layers in a second direction that is substantially parallel to the semiconductor substrate and orthogonal to the first direction;

a first memory pillar extending through the first interconnect layers in a third direction that is substantially vertical to the semiconductor substrate;

a second memory pillar extending through the second interconnect layers in the third direction;

a first film above the first interconnect layers, the first film having a planar shape corresponding to the first interconnect layers and extending in the first direction;

a second film above the second interconnect layers, the second film being separate from the first film in the second direction, having a planar shape corresponding to the second interconnect layers and extending in the first direction;

a first conductive layer between the first interconnect layers and the second interconnect layers and between the first film and the second film, the first conductive layer extending in the first direction and being electrically coupled to a diffusion layer formed in the semiconductor substrate;

a first insulating layer between the first interconnect layers and the first conductive layer; and

a second insulating layer between the second interconnect layers and the first conductive layer,

wherein the first and second films have a compressive stress higher than a silicon oxide film.

18. The device according to claim 17 , wherein:

the first insulating layer is further provided between the first film and the first conductive layer, and

the second insulating layer is further provided between the second film and the first conductive layer.

19. The device according to claim 17 , wherein:

the first and second films include one of amorphous silicon, polysilicon, silicon nitride formed by physical vapor deposition (PVD), and nitrogen-containing tungsten.

20. The device according to claim 17 , wherein:

the first and second films have a compressive stress of an absolute value of 300 MPa or greater.