SEMICONDUCTOR DEVICE

• US 20180053774A1
• Filed: 03/16/2017
• Published: 02/22/2018
• Est. Priority Date: 08/18/2016
• Status: Active Grant

• Current Assignee: Kioxia Corporation
• Original Assignee: Toshiba Memory Corporation (Kioxia Corporation)
• Inventors: SAKAMOTO, Wataru
• Granted Patent: US 10,068,911 B2
• Time in Patent Office: Days
• CPC Class Codes: H01L 29/1037 and non-planar channel resulting from the gate electrode disposition, e.g. within a trench, H01L29/42356
• CPC Class Codes: H01L 29/40114 the electrodes comprising a conductor-insulator-conductor-insulator-semiconductor structure
• CPC Class Codes: H01L 29/40117 the electrodes comprising a charge-trapping insulator
• CPC Class Codes: H10B 41/10 characterised by the top-view layout
• CPC Class Codes: H10B 41/27 the channels comprising vertical portions, e.g. U-shaped channels
• CPC Class Codes: H10B 41/35 with a cell select transistor, e.g. NAND
• CPC Class Codes: H10B 43/10 characterised by the top-view layout
• CPC Class Codes: H10B 43/27 the channels comprising vertical portions, e.g. U-shaped channels
• CPC Class Codes: H10B 43/35 with cell select transistors, e.g. NAND

Abstract

According to one embodiment, a semiconductor device includes a stacked body, a columnar portion, a first charge storage portion, and a second charge storage portion. The stacked body includes a plurality of electrode layers stacked in a first direction. The plurality of electrode layers includes a first electrode layer, and a second electrode layer. The columnar portion extends in the first direction in the stacked body. The first charge storage portion provides between the first electrode layer and the columnar portion. The second charge storage portion provides between the second electrode layer and the columnar portion. A first thickness in a second direction intersecting the first direction of the first charge storage portion between the first electrode layer and the columnar portion is thicker than a second thickness in the second direction of the second charge storage portion between the second electrode layer and the columnar portion.

Claims

1. A semiconductor device comprising:

a stacked body including a plurality of electrode layers stacked on a substrate in a first direction with an insulator interposed between the electrode layers, the plurality of electrode layers including a first electrode layer, and a second electrode layer provided between the first electrode layer and the substrate;

a columnar portion extending in the first direction in the stacked body;

a first charge storage portion provided between the first electrode layer and the columnar portion; and

a second charge storage portion provided between the second electrode layer and the columnar portion,

a first thickness in a second direction intersecting the first direction of the first charge storage portion between the first electrode layer and the columnar portion being thicker than a second thickness in the second direction of the second charge storage portion between the second electrode layer and the columnar portion.

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

a third charge storage portion,

the plurality of electrode layers further include a third electrode layer provided between the first electrode layer and the second electrode layer, and

the third charge storage portion is provided between the third electrode layer and the columnar portion, and a third thickness in the second direction of the third charge storage portion between the third electrode layer and the columnar portion is a thickness not more than the first thickness, and the third thickness is not less than the second thickness.

3. The device according to claim 1, wherein a diameter of the columnar portion in the first electrode layer is larger than a diameter of the columnar portion in the second electrode layer.

4. The device according to claim 1, wherein each of the plurality of electrode layers includes silicon and impurity.

5. The device according to claim 4, wherein a concentration of the impurity in the first electrode layer is higher than a concentration of the impurity in the second electrode layer.

6. The device according to claim 1, wherein each of the plurality of electrode layers contains a metal.

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

a tunnel insulating film provided between the columnar portion and the first charge storage portion, and between the columnar portion and the second charge storage portion;

a first block insulating film provided between the first electrode layer and the first charge storage portion; and

a second block insulating film provided between the second electrode layer and the second charge storage portion.

8. The device according to claim 7, wherein the first inner diameter of the tunnel insulating film between the columnar portion and the first charge storage portion is larger than the second inner diameter of the tunnel insulating film between the columnar portion and the second charge storage portion.

9. The device according to claim 2, further comprising:

a tunnel insulating film provided between the columnar portion and the first charge storage portion, between the columnar portion and the second charge storage portion, and between the columnar portion and the third charge storage portion;

a first block insulating film provided between the first electrode layer and the first charge storage portion;

a second block insulating film provided between the second electrode layer and the second charge storage portion; and

a third block insulating film provided between the third electrode layer and the third charge storage portion,

the first inner diameter of the tunnel insulating film between the columnar portion and the first charge storage portion is larger than the second inner diameter of the tunnel insulating film between the columnar portion and the second charge storage portion, the third inner diameter of the tunnel insulating film between the columnar portion and the third charge storage portion is not more than the first inner diameter, and the third inner diameter is not less than the second inner diameter.

10. A semiconductor device comprising:

a first stacked portion provided on the substrate, the first stacked portion including a first electrode layer and a second electrode layer, the second electrode layer being provided between the substrate and the first electrode layer;

a second stacked portion provided between the substrate and the first stacked portion, the second stacked portion including a third electrode layer and a fourth electrode layer, the fourth electrode layer being provided between the substrate and the third electrode layer;

a first columnar portion provided in the first stacked portion, the first columnar portion extending in a first direction from the first stacked portion to the substrate;

a second columnar portion which is provided in the second stacked portion and extends in the first direction, the second columnar portion being connected to the first columnar portion;

a first charge storage portion provided between the first electrode layer and the first columnar portion;

a second charge storage portion provided between the second electrode layer and the first columnar portion;

a third charge storage portion provided between the third electrode layer and the second columnar portion; and

a fourth charge storage portion provided between the fourth electrode layer and the second columnar portion,

a first thickness in a second direction intersecting the first direction of the first charge storage portion between the first electrode layer and the first columnar portion being thicker than a second thickness in the second direction of the second charge storage portion between the second electrode layer and the first columnar portion, and a third thickness in the second direction of the third charge storage portion between the third electrode layer and the second columnar portion being thicker than a fourth thickness in the second direction of the fourth charge storage portion between the fourth electrode layer and the second columnar portion.

11. The device according to claim 10, wherein the second thickness is less than the third thickness.

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

a fifth charge storage portion;

a sixth charge storage portion;

a fifth electrode layer provided between the first electrode layer and the second electrode layer; and

a sixth electrode layer provided between the third electrode layer and the fourth electrode layer,

the fifth charge storage portion is provided between the fifth electrode layer and the first columnar portion, a fifth thickness in the second direction of the fifth charge storage portion between the fifth electrode layer and the first columnar portion is not more than the first thickness, and the fifth thickness is not less than the second thickness, and

the sixth charge storage portion is provided between the sixth electrode layer and the second columnar portion, a sixth thickness in the second direction of the sixth charge storage portion between the sixth electrode layer and the second columnar portion is not more than the third thickness, and the sixth thickness is not less than the fourth thickness.

13. The device according to claim 10, wherein

the diameter of the first columnar portion in the first electrode layer is larger than the diameter of the second columnar portion in the second electrode layer, and

the diameter of the second columnar portion in the third electrode layer is larger than the diameter of the second columnar portion in the fourth electrode layer.

14. The device according to claim 10, wherein a diameter of a lower end portion of the first columnar portion is smaller than a diameter of an upper end portion of the second columnar portion.

15. The device according to claim 10, wherein each of the first to fourth electrode layers contains silicon and impurity.

16. The device according to claim 15, wherein

a concentration of the impurity in the first electrode layer is higher than a concentration of the impurity in the second electrode layer, and

a concentration of the impurity in the third electrode layer is higher than a concentration of the impurity in the fourth electrode layer.

17. The device according to claim 10, wherein each of the first to the fourth electrode layers contains a metal.

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

a tunnel insulating film provided between the first columnar portion and the first charge storage portion, between the first columnar portion and the second charge storage portion, between the second columnar portion and the third charge storage portion, and between the second columnar portion and the fourth charge storage portion;

a first block insulating film provided between the first electrode layer and the first charge storage portion;

a second block insulating film provided between the second electrode layer and the second charge storage portion;

a third block insulating film provided between the third electrode layer and the third charge storage portion; and

a fourth block insulating film provided between the fourth electrode layer and the fourth charge storage portion.

19. The device according to claim 18, wherein

a first inner diameter of the tunnel insulating film between the first columnar portion and the first charge storage portion is larger than a second inner diameter of the tunnel insulating film between the first columnar portion and the second charge storage portion, and

a third inner diameter of the tunnel insulating film between the second columnar portion and the third charge storage portion is larger than a fourth inner diameter of the tunnel insulating film between the second columnar portion and the fourth charge storage portion.

20. The device according to claim 19, wherein the third inner diameter is larger than the second inner diameter.