Semiconductor memory device and method for manufacturing same

• US 8,288,816 B2
• Filed: 06/11/2010
• Issued: 10/16/2012
• Est. Priority Date: 03/05/2010
• Status: Active Grant

• Current Assignee: Toshiba Memory Corporation (Kioxia Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Komori, Yosuke, Kidoh, Masaru, Katsumata, Ryota
• Primary Examiner(s): Dickey, Thomas L
• Application Number:
  US12/813,895
• Publication Number:
  US 20110215394A1
• Time in Patent Office: 858 Days
• Field of Search: 257/324, 365/185.17, 438/270
• US Class Current: 257/324
• CPC Class Codes: G11C 16/0483 comprising cells having several storage transistors connected in series
• CPC Class Codes: G11C 16/26 Sensing or reading circuits; Data output circuits
• CPC Class Codes: H01L 27/0688 Integrated circuits having a three-dimensional layout
• 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 semiconductor memory device includes a base, a stacked body, a memory film, a channel body, a contact plug, a global bit line, and a plurality of local bit lines. The base has a substrate and a peripheral circuit formed on the substrate. The stacked body has a plurality of conductive layers and insulating layers stacked alternately above the base. The memory film includes a charge storage film provided on an inner wall of a memory hole formed in a stacking direction of the stacked body. The channel body is provided inside the memory film in the memory hole. The contact plug is provided by piercing the stacked body. The global bit line is provided between the peripheral circuit and the stacked body and connected to a lower end portion of the contact plug. The plurality of local bit lines are provided above the stacked body and divided in an extending direction of the plurality of local bit lines. The plurality of local bit lines are connected to the channel body and commonly connected to the global bit line through the contact plug.

Claims

1. A semiconductor memory device comprising:

a base having a substrate and a peripheral circuit formed on the substrate;

a stacked body having a plurality of conductive layers and insulating layers stacked alternately above the base;

a memory film including a charge storage film provided on an inner wall of a memory hole formed in a stacking direction of the stacked body;

a channel body provided inside the memory film in the memory hole;

a contact plug provided by piercing the stacked body;

a global bit line provided between the peripheral circuit and the stacked body and connected to a lower end portion of the contact plug; and

a plurality of local bit lines provided above the stacked body and divided in an extending direction of the plurality of local bit lines, the plurality of local bit lines connected to the channel body and commonly connected to the global bit line through the contact plug.

2. The device according to claim 1, wherein the adjacent two local bit lines placing the contact plug between the two local bit lines in the extending direction are commonly connected to the contact plug.

3. The device according to claim 1, further comprising a source line electrically operable independently of the local bit lines, the global bit line and the conductive layers.

4. The device according to claim 3, wherein

the source line is provided on the stacked body,

the channel body is formed in a U-shape configuration having a pair of columnar portions extending in a stacking direction of the stacked body and a connection buried in a bottom of the stacked body and connecting the pair of columnar portions.

5. The device according to claim 3, wherein

the channel body includes:

a memory string channel body connected between one of the local bit lines and the source line; and

a contact channel body connected between one of the local bit lines and the contact plug.

6. The device according to claim 5, wherein

a plurality of the contact channel body are connected in parallel between one of the local bit lines and the contact plug.

7. The device according to claim 5, wherein

the memory string channel body is formed in a U-shape configuration having a pair of columnar portions extending in a stacking direction of the stacked body and a connection buried in a bottom of the stacked body and connecting the pair of columnar portions,

the contact channel body has a conductive body having a width larger than a combined width of the pair of columnar portions.

8. The device according to claim 5, further comprising an interconnection provided in a layer equal to a layer being provided with the local bit lines, formed of a material equal to a material forming the local bit lines and connecting the contact channel body to the contact plug.

9. The device according to claim 1, wherein

the global bit line has a width and a extending direction equal to a width and a extending direction of the local bit lines, and is laid out immediately below one of the local bit lines.

10. The device according to claim 5, further comprising a first selection gate configured to switch turning on and off between the contact channel body and one of the local bit lines and a second selection gate configured to switch turning on and off between the contact channel body and the contact plug.

11. The device according to claim 10, wherein

the contact channel body connected to a non-selection local bit line of the local bit lines during reading is blocked to the global bit line by the first selection gate and the second selection gate.

12. A method for manufacturing a semiconductor memory device comprising:

forming a peripheral circuit on a surface of a substrate;

forming a global bit line above the peripheral circuit;

alternately stacking a plurality of conductive layers with a plurality of insulating layers above the global bit line to form a stacked body;

forming a memory hole in the stacked body;

forming a memory film including a charge storage film on an inner wall of the memory hole;

forming a channel body inside the memory film in the memory hole;

forming a contact plug connected to the global bit line by piercing the stacked body; and

forming a plurality of local bit lines above the stacked body, the plurality of local bit lines connected to the channel body and the contact plug and divided in an extending direction of the plurality of local bit lines.

13. The method according to claim 12, wherein the global bit line is simultaneously formed with a lower layer interconnection using a material equal to a material forming the lower layer interconnection in forming the lower layer interconnection to be connected to the peripheral circuit above the peripheral circuit.

14. The method according to claim 13, wherein the local bit lines are simultaneously formed with an upper layer interconnection using a material equal to a material forming an upper layer interconnection in forming the upper layer interconnection to be connected to the lower layer interconnection above the stacked body.