memory devices

Abstract

This invention reduces the manufacturing cost of memory devices. An embodiment of the memory device 1 includes a plurality of conductive layers 24, an insulating film 51, and a plurality of contact plugs CC, arranged throughout layers TLCA and TUCA. Each of the plurality of conductive layers 24 has a high-dielectric film 54. The upper surface of the insulating film 51 has a step along a stepped shape formed by the plurality of conductive layers 24a included in the layer TLCA. The insulating film 51 is thicker than the conductive layers 24a and includes a high-dielectric film 52 of the same material as the high-dielectric film 54. The plurality of contact plugs includes a plurality of contact plugs CCa respectively connected to the plurality of conductive layers 24a. Each of the plurality of contact plugs CCa includes a sub-contact plug LCC having a portion passing through the layer TLCA and the insulating film 51, and a sub-contact plug UCC having a portion passing through the layer TUCA.

Claims

1. A memory device comprising: a plurality of conductive layers, which are disposed in a first region and a second region in a first direction, and disposed apart from each other in a second direction intersecting the first direction, and are arranged throughout a plurality of layers including a first layer and a second layer above the first layer, each having a platform portion in the second region that does not overlap with a conductive layer disposed on the upper layer in the same layer of the plurality of conductive layers and a first high-dielectric film; and a memory pillar disposed in the first region through the plurality of conductive layers in the second direction, and the portion of the pillar intersecting the plurality of conductive layers functions as a memory cell. An insulating film, the upper surface of which has a stepped shape formed by a plurality of platform portions of a plurality of first conductive layers included in the plurality of conductive layers, and is thicker than the plurality of first conductive layers, includes a second high-dielectric film of the same material as the first high-dielectric film; and a plurality of contact plugs, which are equal to the second region and are respectively connected to the plurality of platform portions of the plurality of conductive layers; and the plurality of contact plugs include: a plurality of first contact plugs, which are respectively connected to the plurality of first conductive layers, and each includes a first sub-contact plug and a second sub-contact plug, the first sub-contact plug having a portion that passes through the first layer including the insulating film in the first layer, and the second sub-contact plug having a portion that passes through the second layer.

2. The memory device of claim 1, wherein the thickness of the first high-dielectric film and the second high-dielectric film are substantially equal.

3. The memory device of claim 1, wherein the insulating film includes a first insulating member having a portion surrounded by the second high-dielectric film; and the first sub-contact plug is inserted in the portion intersecting with the insulating film, having a portion sandwiching the first insulating member in the second direction.

4. The memory device of claim 1, wherein the first sub-contact plug has a portion extending along the first direction with a thickness substantially the same as that of the first high-dielectric film in the connection portion of the first conductive layer corresponding to the plurality of first conductive layers.

5. The memory device of claim 1, wherein each of the plurality of conductive layers further comprises a metal film disposed inside the first high-dielectric film and a conductive member disposed inside the metal film and different from the metal film; and the conductive member comprises tungsten.

6. The memory device of claim 1, wherein each of the plurality of conductive layers further includes a conductive member disposed inside the first high-dielectric film; and the conductive member includes molybdenum.

7. The memory device of claim 1, wherein the insulating film includes a first insulating member having a portion surrounded by the second high-dielectric film; and in a cross-section along a direction orthogonal to the second direction, the cross-sectional area of ​​the portion of the first sub-contact plug that intersects with the first insulating member is greater than the cross-sectional area of ​​the portion of the first sub-contact plug that intersects with the portion of the plurality of first conductive layers connected to the first sub-contact plug.

8. The memory device of claim 1, wherein the insulating film includes a first insulating member having a portion surrounded by the second high-dielectric film; and in a cross-section along a direction orthogonal to the second direction, the cross-sectional area of ​​the portion of the first sub-contact plug that intersects with the first insulating member is approximately equal to the cross-sectional area of ​​the portion of the first sub-contact plug that intersects with the portion of the plurality of first conductive layers connected to the first sub-contact plug.

9. The memory device of claim 1 further comprises: a second insulating member disposed between the first sub-contact plug and the second high-dielectric film.

10. The memory device of claim 1, wherein the side surface shapes of the plurality of first contact plugs are discontinuous at the boundary between the first layer and the second layer.

11. The memory device of claim 10, wherein the plurality of layers further includes a third layer above the second layer; and the plurality of conductive layers further include: a plurality of second conductive layers contained in the second layer, and a plurality of third conductive layers contained in the third layer; the plurality of contact plugs further include: a plurality of second contact plugs, each having a portion passing through the second layer and the third layer, and respectively connected to the plurality of second conductive layers; the second sub-contact plugs of the plurality of first contact plugs have a portion passing through the third layer; at the boundary between the second layer and the third layer, the side surface shapes of the plurality of second contact plugs are continuous, and the side surface shapes of the second sub-contact plugs are continuous.

12. The memory device of claim 1, wherein, in a cross-section along a direction orthogonal to the second direction, the cross-sectional area of ​​the end portion of the first sub-contact plug at the boundary between the first and second layers is greater than the cross-sectional area of ​​the end portion of the second sub-contact plug at the boundary.

13. A memory device comprising: a plurality of conductive layers, each disposed in a first region and a second region in a first direction, and disposed apart from each other in a second direction intersecting the first direction, and distributed throughout a plurality of layers including a first layer and a second layer above the first layer; each having a platform portion in the second region that does not overlap with a conductive layer disposed on the upper layer of the plurality of conductive layers in the same layer; and comprising a plurality of first conductive layers included in the first layer, and at least one intermediate conductive layer included in the first layer and disposed closer to the boundary between the first layer and the second layer than the plurality of first conductive layers; and a memory pillar disposed in the first region through the plurality of conductive layers in the second direction, and functioning as a memory cell at one intersection with the plurality of conductive layers. An insulating film is provided with a stepped shape along a stepped shape formed by a plurality of platform portions of a plurality of first conductive layers on its upper surface; and a plurality of contact plugs are provided in the second region and are respectively connected to the plurality of platform portions of the plurality of conductive layers; and the plurality of contact plugs include a plurality of first contact plugs respectively connected to the plurality of first conductive layers and at least one second contact plug respectively connected to the at least one intermediate conductive layer; each of the plurality of first contact plugs includes: a first sub-contact plug having a portion that passes through the first layer including the insulating film within the first layer; and a second sub-contact plug having a portion that passes through the second layer; the at least one second contact plug having a portion that passes through the first layer and the second layer and is disposed away from the insulating film.

14. The memory device of claim 13, wherein at the boundary between the first layer and the second layer, the side shapes of the plurality of first contact plugs are discontinuous, and the side shapes of the second contact plugs are continuous.

15. The memory device of claim 13 further comprises: a first insulating layer disposed in such a way that a step difference is formed by the plurality of platform portions of the plurality of first conductive layers and the platform portion of the intermediate conductive layer, the material being different from the insulating film.

16. The memory device of claim 15 further comprises: a second insulating layer disposed in such a way that a step difference is formed by a plurality of platform portions of the plurality of second conductive layers included in the plurality of conductive layers; and an insulating film of a different material from the second insulating layer is not disposed between the plurality of platform portions of the plurality of second conductive layers and the second insulating layer.

17. A memory device comprising: a plurality of conductive layers, each disposed in a first region and a second region arranged in a first direction and disposed away from each other in a second direction intersecting the first direction, and each having a platform portion in the second region that does not overlap with an upper conductive layer of the plurality of conductive layers and a first high-dielectric film; and a memory pillar disposed in the first region through the plurality of conductive layers in the second direction, and the portion of the pillar intersecting the plurality of conductive layers functions as a memory cell. An insulating film having a stepped shape along a stepped shape formed by a plurality of platform portions of the plurality of conductive layers on its upper surface, and being thicker than the plurality of conductive layers, comprising a second high-dielectric film of the same material as the first high-dielectric film; and a plurality of contact plugs, which are equal to the plurality of platform portions of the plurality of conductive layers respectively connected to the plurality of platform portions of the plurality of conductive layers through the insulating film in the second region.

18. The memory device of claim 17, wherein the thickness of the first high-dielectric film and the second high-dielectric film are substantially equal.

19. The memory device of claim 17, wherein the insulating film includes a first insulating member having a portion surrounded by the second high-dielectric film; and the plurality of contact plugs of the insulating film intersect the insulating film, each having a portion sandwiching the first insulating member in the second direction.

20. The memory device of claim 17, wherein the plurality of contact plugs through the insulating film in the connection portions of the conductive layers corresponding to the plurality of conductive layers each have a portion extending along the first direction with a thickness substantially the same as that of the first high-dielectric film.

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