NONVOLATILE SEMICONDUCTOR STORAGE APPARATUS AND METHOD FOR MANUFACTURING THE SAME

• US 20080099819A1
• Filed: 10/17/2007
• Published: 05/01/2008
• Est. Priority Date: 10/17/2006
• Status: Active Grant

• Current Assignee: Kioxia Corporation
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: KITO, Masaru, INOUE, Hirofumi
• Granted Patent: US 7,952,136 B2
• Time in Patent Office: Days
• US Class Current: 257/315
• CPC Class Codes: G11C 16/10 Programming or data input circuits
• CPC Class Codes: H01L 27/0207 Geometrical layout of the components, e.g. computer aided design; custom LSI, semi-custom LSI, standard cell technique
• CPC Class Codes: H01L 27/0688 Integrated circuits having a three-dimensional layout
• CPC Class Codes: H01L 27/105 including field-effect components
• CPC Class Codes: H10B 41/27 the channels comprising vertical portions, e.g. U-shaped channels
• CPC Class Codes: H10B 43/20 characterised by three-dimensional arrangements, e.g. with cells on different height levels
• 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 an aspect of the present invention, there is provided a nonvolatile semiconductor storage apparatus including: a substrate; a columnar semiconductor disposed perpendicular to the substrate; a charge storage laminated film disposed around the columnar semiconductor; a first conductor layer that is in contact with the charge storage laminated film and that has a first end portion having a first end face; a second conductor layer that is in contact with the charge storage laminated film, that is separated from the first conductor layer and that has a second end portion having a second end face; a first contact plug disposed on the first end face; and a second contact plug disposed on the second end face.

Claims

1. A nonvolatile semiconductor storage apparatus comprising:

a substrate;

an insulating layer disposed on the substrate;

a columnar semiconductor disposed perpendicular to the substrate;

a laminated film comprising;

a first insulating film disposed around the columnar semiconductor,

a charge storage film disposed around the first insulating film, and

a second insulating film disposed around the charge storage film;

a first conductor layer that is disposed on the insulating layer and that is in contact with the laminated film;

a first interlayer insulating layer disposed on the first conductor layer;

a second conductor layer that is disposed on the first interlayer insulating layer and that is in contact with the laminated film;

a first contact plug that is connected to the first conductor layer; and

a second contact plug that is connected to the second conductor layer;

wherein the first conductor layer comprises a first end portion that is bent upwardly;

wherein the second conductor layer comprises a second end portion that is bent upwardly;

wherein the first end portion comprises a first end face;

wherein the second end portion comprises a second end face;

wherein the first contact plug is disposed on the first end face; and

wherein the second contact plug is disposed on the second end face.

2. The nonvolatile semiconductor storage apparatus according to claim 1, wherein the columnar semiconductor, the laminated film and the first conductor layer form a first memory cell that operates in a depression mode;

and

wherein the columnar semiconductor, the laminated film and the second conductor layer form a second memory cell that operates in the depression mode.

3. The nonvolatile semiconductor storage apparatus according to claim 2, wherein the first memory cell and the second memory cell form a memory string.

4. The nonvolatile semiconductor storage apparatus according to claim 1, wherein the first end face has a width that is equal to or larger than a thickness of the first conductor layer.

5. The nonvolatile semiconductor storage apparatus according to claim 1, wherein the second end face is disposed in the same plane as and the first end face.

6. The nonvolatile semiconductor storage apparatus according to claim 1, wherein the first conductor layer further comprise a first central portion where the first conductor layer is in contact with the laminated film;

and

wherein the first end portion is made of the same material as the first central layer.

7. The nonvolatile semiconductor storage apparatus according to claim 1, wherein the first end portion forms an angle that is equal to or larger than 45 degree with a surface of the substrate.

8. The nonvolatile semiconductor storage apparatus according to claim 6, wherein the insulating layer comprises:

a concave portion that is in contact with the first central portion, and

a convex portion that is in contact with the first end portion.

9. The nonvolatile semiconductor storage apparatus according to claim 1, wherein the first end portion has a straight shape.

10. The nonvolatile semiconductor storage apparatus according to claim 1, wherein the first end portion has a curved shape.

11. A method for manufacturing a nonvolatile semiconductor storage apparatus, comprising:

performing an opening formation process, comprising;

depositing an insulating film on a substrate, and

forming a concave portion and a convex portion in the insulating film;

performing a deposition process, comprising;

depositing a first conductor film along the concave portion, a sidewall of the concave portion and the convex portion, and

depositing a first interlayer insulating film on the first conductor film;

performing a planarization process, comprising;

removing the first interlayer insulating film over the convex portion, and

removing the first conductor film over the convex portion; and

forming a contact plug on an end face of the first conductor film exposed through the planarization process.

12. The method according to claim 11, wherein the step of performing the deposition process further comprises:

depositing a second conductor film on the first interlayer insulating film, and

depositing a second interlayer insulating film on the second conductor film; and

wherein the step of performing the planarization process further comprises;

removing the second interlayer insulating film over the convex portion, and

removing the second conductor film over the convex portion.

13. The method according to claim 12, wherein a depth of the concave portion formed through the opening formation process is larger than a total thickness of the first conductor film, the first interlayer insulating film, the second conductor film and the second interlayer insulating film deposited through the deposition process.

14. The method according to claim 11, wherein the step of performing the deposition process comprises:

alternatively depositing a plurality of conductor films and a plurality of interlayer insulating films; and

wherein the step of performing the planarization process comprises;

removing the plurality of conductor films and the plurality of interlayer insulating films over the convex portion.

15. The method according to claim 14, wherein a depth of the concave portion formed through the opening formation process is larger than a total thickness of the plurality of conductor films and the plurality of interlayer insulating films deposited through the deposition process.

16. The method according to claim 11, wherein the concave portion is formed so that the sidewall of the convex portion becomes perpendicular to a surface of the substrate through the opening formation process.

17. The method according to claim 11, wherein the concave portion is formed so that the sidewall of the convex portion forms an angle that is equal to or larger than 45 degree with a surface of the substrate through the opening formation process.

18. The method according to claim 11, wherein the concave portion is formed so that the sidewall of the convex portion has a curved shape through the opening formation process.

19. A nonvolatile semiconductor storage apparatus comprising:

a substrate;

a columnar semiconductor formed perpendicular to the substrate;

a charge storage laminated film formed around the columnar semiconductor;

a first conductor layer that is in contact with the charge storage laminated film; and

a second conductor layer that is separated from the first conductor layer and that is in contact with the charge storage laminated film;

wherein an end face of the first conductor layer and an end face of the second conductor layer are formed in a common plane that is parallel with the substrate.