Methods and apparatus for three-dimensional NAND non-volatile memory devices with side source line and mechanical support

Patent metadata

Field	Value
Publication number	US-9780112-B2
Application number	US-201514922365-A
Country	US
Kind code	B2
Filing date	Oct 26, 2015
Priority date	Oct 26, 2015
Publication date	Oct 3, 2017
Grant date	Oct 3, 2017

Abstract

A method of fabricating a monolithic three dimensional memory structure is provided. The method includes forming a stack of alternating word line and dielectric layers above a substrate, forming a source line above the substrate, forming a memory hole extending through the alternating word line and dielectric layers and the source line, and forming a mechanical support element on the substrate adjacent to the memory hole.

First claim

The invention claimed is:

1. A three-dimensional stacked non-volatile memory structure comprising:
a source line disposed above a substrate;
a stack disposed above the substrate, the stack comprising alternating word line and dielectric layers;
a plurality of NAND strings of memory cells formed in memory holes which extend through the source line and the alternating word line and dielectric layers, each memory cell comprising a control gate formed by one of the word line layers; and
a mechanical support element disposed on the substrate adjacent the plurality of NAND strings, the mechanical support element extending through the source line.

2. The three-dimensional stacked non-volatile memory structure of claim 1 , wherein the mechanical support element comprises a plurality of mechanical support elements.

3. The three-dimensional stacked non-volatile memory structure of claim 2 , wherein the plurality of mechanical support elements is disposed along a peripheral region of the plurality of NAND strings.

4. The three-dimensional stacked non-volatile memory structure of claim 1 , wherein the mechanical support element comprises a first set of mechanical support elements disposed at a first region of the memory structure, a second set of mechanical support elements disposed at a second region of the memory structure, and a third mechanical support element disposed at a third region of the memory structure.

5. The three-dimensional stacked non-volatile memory structure of claim 4 , wherein the first region comprises a first peripheral region of the memory structure, the second region comprises a second peripheral region of the memory structure, and the third region comprises a central region of the memory structure.

6. The three-dimensional stacked non-volatile memory structure of claim 1 , wherein the mechanical support element extends to a height substantially equal to a height of a top surface of the source line.

7. The three-dimensional stacked non-volatile memory structure of claim 1 , wherein the mechanical support element has a height between about 500 angstroms and about 3500 angstroms.

8. The three-dimensional stacked non-volatile memory structure of claim 1 , wherein the mechanical support element comprises polysilicon.

9. The three-dimensional stacked non-volatile memory structure of claim 1 , wherein each of the NAND strings comprises a vertical channel comprising a peripheral exterior in contact with the source line.

10. The three-dimensional stacked non-volatile memory structure of claim 9 , wherein the vertical channel comprises polysilicon.

Assignees

• Sandisk Technologies Inc
• Sandisk Technologies Llc

Inventors

• Liu Jin
• Ge Chun
• Alsmeier Johann

Classifications

• H01L27/1157

  Electricity · mapped topic

• H01L27/11582 Primary

  Electricity · mapped topic

• H01L27/11573

  Electricity · mapped topic

• H01L27/11556

  Electricity · mapped topic

• H01L27/11529

  Electricity · mapped topic