NONVOLATILE SEMICONDUCTOR MEMORY DEVICE AND METHOD FOR MANUFACTURING THE SAME

• US 20110309432A1
• Filed: 12/29/2010
• Published: 12/22/2011
• Est. Priority Date: 06/22/2010
• Status: Active Grant

• Current Assignee: Kioxia Corporation
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: ISHIHARA, Takamitsu, Aochi, Hideaki
• Granted Patent: US 8,455,941 B2
• Time in Patent Office: Days
• US Class Current: 257/324
• CPC Class Codes: G11C 16/0466 comprising cells with charge storage in an insulating layer, e.g. metal-nitride-oxide-silicon [MNOS], silicon-oxide-nitride-oxide-silicon [SONOS] G11C16/0483, G11C16/0491 take precedence
• CPC Class Codes: H01L 29/66833 with a charge trapping gate insulator, e.g. MNOS transistors
• CPC Class Codes: H01L 29/7926 Vertical transistors, i.e. transistors having source and drain not in the same horizontal plane
• 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 43/40 characterised by the peripheral circuit region

Abstract

According to one embodiment, a nonvolatile semiconductor memory device includes a stacked body including electrode films stacked in a first direction; a conductive pillar piercing the stacked body in the first direction; a inner insulating film; a semiconductor pillar; an intermediate insulating film; a memory layer; and an outer insulating film. The inner insulating film, the semiconductor pillar, the intermediate insulating film, the memory layer and the outer insulating film are provided between the conductive pillar and the electrode films. The inner insulating film is provided around a side face of the conductive pillar. The semiconductor pillar is provided around a side face of the inner insulating film. The intermediate insulating film is provided around a side face of the semiconductor pillar. The memory layer is provided around a side face of the intermediate insulating film. The outer insulating film is provided around a side face of the memory layer.

Claims

1. A nonvolatile semiconductor memory device, comprising:

a first stacked body including a plurality of first electrode films stacked in a first direction and a first inter-electrode insulating film provided between the plurality of first electrode films;

a first conductive pillar piercing the first stacked body in the first direction;

a first pillar inner insulating film provided between the first conductive pillar and the first electrode films, the first pillar inner insulating film being provided around a side face of the first conductive pillar;

a first semiconductor pillar provided between the first pillar inner insulating film and the first electrode films to pierce the first stacked body along the first direction, the first semiconductor pillar being provided around a side face of the first pillar inner insulating film;

a first pillar intermediate insulating film provided between the first semiconductor pillar and the first electrode films, the first pillar intermediate insulating film being provided around a side face of the first semiconductor pillar;

a first pillar memory layer provided between the first pillar intermediate insulating film and the first electrode films, the first pillar memory layer being provided around a side face of the first pillar intermediate insulating film; and

a first pillar outer insulating film provided between the first pillar memory layer and the first electrode films, the first pillar outer insulating film being provided around a side face of the first pillar memory layer.

2. The device according to claim 1, further comprising a control unit electrically connected to the plurality of first electrode films and the first conductive pillar to control a state of a charge stored in the first pillar memory layer,

the control unit applying a voltage to the first conductive pillar, the voltage being higher than a voltage applied to the first electrode films in an operation of performing at least one selected from injecting holes into the first pillar memory layer and ejecting electrons from the first pillar memory layer.

3. The device according to claim 1, further comprising a substrate having a major surface,

the first stacked body being provided on the major surface of the substrate,

the first direction being perpendicular to the major surface.

4. The device according to claim 1, wherein a cross section of the first semiconductor pillar when cut by a plane perpendicular to the first direction is circular or flattened circular.

5. The device according to claim 1, wherein:

the first pillar inner insulating film extends between the first conductive pillar and the first inter-electrode insulating film;

the first pillar intermediate insulating film extends between the first semiconductor pillar and the first inter-electrode insulating film;

the first pillar memory layer extends between the first pillar intermediate insulating film and the first inter-electrode insulating film; and

the first pillar outer insulating film extends between the first pillar memory layer and the first inter-electrode insulating film.

6. The device according to claim 1, wherein the first conductive pillar includes at least one selected from amorphous silicon and polysilicon.

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

a first selection gate electrode stacked with the first stacked body in the first direction, the first selection gate electrode being pierced by the first semiconductor pillar; and

a second selection gate electrode stacked with the first stacked body in the first direction,

wherein the first stacked body is disposed between the first selection gate electrode and the second selection gate electrode, and

the first and second selection gate electrodes are pierced by the first semiconductor pillar.

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

a second stacked body arranged with the first stacked body in a second direction perpendicular to the first direction, the second stacked body including a plurality of second electrode films stacked in the first direction and a second inter-electrode insulating film provided between the plurality of second electrode films;

a second conductive pillar piercing the second stacked body in the first direction;

a second pillar inner insulating film provided between the second conductive pillar and the second electrode films, the second pillar inner insulating film being provided around a side face of the second conductive pillar;

a second semiconductor pillar provided between the second pillar inner insulating film and the second electrode films to pierce the second stacked body in the first direction, the second semiconductor pillar being provided around a side face of the second pillar inner insulating film;

a second pillar intermediate insulating film provided between the second semiconductor pillar and the second electrode films, the second pillar intermediate insulating film being provided around a side face of the second semiconductor pillar;

a second pillar memory layer provided between the second pillar intermediate insulating film and the second electrode films, the second pillar memory layer being provided around a side face of the second pillar intermediate insulating film;

a second pillar outer insulating film provided between the second pillar memory layer and the second electrode films, the second pillar outer insulating film being provided around a side face of the second pillar memory layer; and

a semiconductor connection portion electrically connecting a one end of the first semiconductor pillar to a one end of the second semiconductor pillar.

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

a first selection gate electrode stacked with the first stacked body in the first direction, the first selection gate electrode being pierced by the first semiconductor pillar;

a second selection gate electrode stacked with the second stacked body in the first direction, the second selection gate electrode being pierced by the second semiconductor pillar;

a first interconnect electrically connected to an other end of the first semiconductor pillar;

a second interconnect electrically connected to an other end of the second semiconductor pillar; and

a third interconnect electrically connected to at least one selected from a one end of the first conductive pillar and a one end of the second conductive pillar.

10. The device according to claim 9, wherein:

the first electrode films and the second electrode films have portions extending in a third direction perpendicular to the first direction and the second direction;

the first interconnect has a portion extending along the second direction; and

the second interconnect has a portion extending along the third direction.

11. The device according to claim 9, wherein:

at least a part of the first interconnect is disposed between the third interconnect and the first stacked body; and

the first conductive pillar pierces the first interconnect along the first direction.

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

a core connection portion electrically connecting a one end of the first conductive pillar to a one end of the second conductive pillar; and

a connection portion inner insulating film provided between the semiconductor connection portion and the core connection portion.

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

a connection portion conductive layer provided opposing the semiconductor connection portion;

a connection portion intermediate insulating film provided between the semiconductor connection portion and the connection portion conductive layer;

a connection portion memory layer provided between the connection portion intermediate insulating film and the connection portion conductive layer; and

a connection portion outer insulating film provided between the connection portion memory layer and the connection portion conductive layer.

14. The device according to claim 8, wherein each of the plurality of first electrode films is positioned in a plane identical to each of the plurality of second electrode films, respectively.

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

a second stacked body arranged with the first stacked body in a second direction perpendicular to the first direction, the second stacked body including a plurality of second electrode films stacked in the first direction and a second inter-electrode insulating film provided between the plurality of second electrode films;

a second conductive pillar piercing the second stacked body in the first direction;

a second pillar inner insulating film provided between the second conductive pillar and the second electrode films, the second pillar inner insulating film being provided around a side face of the second conductive pillar;

a second semiconductor pillar provided between the second pillar inner insulating film and the second electrode films to pierce the second stacked body in the first direction, the second semiconductor pillar being provided around a side face of the second pillar inner insulating film;

a second pillar intermediate insulating film provided between the second semiconductor pillar and the second electrode films, the second pillar intermediate insulating film being provided around a side face of the second semiconductor pillar;

a second pillar memory layer provided between the second pillar intermediate insulating film and the second electrode films, the second pillar memory layer being provided around a side face of the second pillar intermediate insulating film;

a second pillar outer insulating film provided between the second pillar memory layer and the second electrode films, the second pillar outer insulating film being provided around a side face of the second pillar memory layer;

a semiconductor connection portion electrically connecting a one end of the first semiconductor pillar to a one end of the second semiconductor pillar;

a first selection gate electrode stacked with the first stacked body in the first direction, the first selection gate electrode being pierced by the first semiconductor pillar;

a second selection gate electrode stacked with the second stacked body in the first direction, a second selection gate electrode being pierced by the second semiconductor pillar;

a first interconnect electrically connected to an other end of the first semiconductor pillar;

a second interconnect electrically connected to an other end of the second semiconductor pillar; and

a third interconnect electrically connected to at least one selected from a one end of the first conductive pillar and a one end of the second conductive pillar,

the first electrode films, the second electrode films, the first selection gate electrode, and the second selection gate electrode having portions extending in a third direction perpendicular to the first direction and the second direction,

the first interconnect and the second interconnect having portions extending along the second direction,

the semiconductor connection portion extending in a direction oblique to the second direction and the third direction.

16. The device according to claim 15, wherein:

at least a part of the first interconnect is disposed between the third interconnect and the first stacked body; and

the first conductive pillar pierces the first interconnect along the first direction.

17. The device according to claim 15, further comprising:

a core connection portion electrically connecting an other end of the first conductive pillar to an other end of the second conductive pillar; and

a connection portion inner insulating film provided between the semiconductor connection portion and the core connection portion.

18. The device according to claim 15, wherein each of the plurality of first electrode films is positioned in a plane identical to each of the plurality of second electrode films, respectively.

19. The device according to claim 15, wherein a distance between the first interconnect and the first stacked body is identical to a distance between the second interconnect and the first stacked body.

20. A method for manufacturing a nonvolatile semiconductor memory device, comprising:

making a through-hole piercing a stacked body and an inter-layer insulating film along a first direction, the inter-layer insulating film being stacked with the stacked body, the stacked body including a plurality of electrode films stacked in the first direction and an inter-electrode insulating film provided between the plurality of electrode films;

depositing a stacked film of a film used to form a pillar outer insulating film, a film used to form a pillar memory layer, a film used to form a pillar intermediate insulating film, a film used to form a semiconductor pillar, a film used to form a pillar inner insulating film, and a film used to form a conductive pillar sequentially on an inner wall of the through-hole;

exposing the film used to form the pillar outer insulating film by performing etch-back of at least a portion of the inter-layer insulating film;

exposing a side face of the film used to form the semiconductor pillar by removing the exposed film used to form the pillar outer insulating film, the film used to form the pillar memory layer, and the film used to form the pillar intermediate insulating film; and

forming a film used to form an interconnect, the film used to form the interconnect being electrically connected to the exposed side face of the film used to form the semiconductor pillar.