Shallow trench isolation recess control

Patent metadata

Field	Value
Publication number	US-2024074158-A1
Application number	US-202318234145-A
Country	US
Kind code	A1
Filing date	Aug 15, 2023
Priority date	Aug 30, 2022
Publication date	Feb 29, 2024
Grant date	—

Abstract

A variety of applications can include an apparatus having a memory device in which, during fabrication of the memory device, processing a dielectric isolation region about an active area of a memory cell is controlled to provide enhanced electric isolation of a data line contact to the memory cell with respect to a cell contact to the memory cell. A portion of the dielectric isolation region can be recessed, creating a corner between the dielectric isolation region and a conductive region, where the conductive region is material for the active area. The corner can be filled with a dielectric material and the data line contact can be formed contacting the dielectric material and coupled to the conductive region. The cell contact can be formed to the memory cell contacting the dielectric material such that the dielectric material is between the cell contact and the data line contact.

First claim

What is claimed is:

1 . A method of forming a memory device, the method comprising:
recessing a portion of a dielectric isolation region, creating a corner between the dielectric isolation region and a conductive region, the conductive region being material for an active area of an access device for a memory cell of the memory device; filling the corner with a dielectric material, the dielectric material being different from material of the dielectric isolation region; forming a data line contact contacting the dielectric material and coupled to the conductive region; and forming a cell contact to the memory cell contacting the dielectric material, replacing a portion of the dielectric isolation region such that the dielectric material is between the cell contact and the data line contact.

2 . The method of claim 1 , wherein filling the corner with the dielectric material includes forming the dielectric material by atomic layer deposition.

3 . The method of claim 2 , wherein the dielectric material is a non-oxide dielectric.

4 . The method of claim 1 , wherein forming the data line contact to the conductive region includes forming a silicon plug between the data line contact and the conductive region after recessing the conductive region.

5 . The method of claim 1 , wherein the method includes forming a capacitor coupled to the cell contact.

6 . A method of forming a memory device, the method comprising:
forming a first opening through sacrificial dielectric regions, exposing a top of a conductive region and exposing a portion of a shallow trench isolation region adjacent to and contacting the conductive region, the conductive region being material for an active area of an access device for a memory cell of the memory device; forming a liner of dielectric material in the first opening, covering the exposed top of the conductive region and the exposed portion of the shallow trench isolation region; removing portions of the liner while leaving a corner of the dielectric material on the shallow trench isolation regions about the top of the conductive region; removing portions of the conductive region, while maintaining the corner of the dielectric material on the shallow trench isolation region; forming a data line contact contacting the corner and coupled to a remaining portion of the conductive region after removing the portions of the conductive region; and forming a cell contact separated from the data line contact by the corner of the dielectric material.

7 . The method of claim 6 , wherein forming the first opening includes selectively etching the sacrificial dielectric regions substantially without etching the conductive region.

8 . The method of claim 6 , wherein forming the liner of dielectric material includes forming the liner by atomic layer deposition.

9 . The method of claim 6 , wherein removing the portions of the liner includes performing an isotropic removal of the portions of the liner.

10 . The method of claim 9 , wherein performing the isotropic removal includes performing a wet etch of the liner.

11 . The method of claim 6 , wherein the dielectric material is a non-oxide dielectric.

12 . The method of claim 11 , wherein the non-oxide dielectric includes one or more of a dielectric nitride or silicon carbide.

13 . The method of claim 6 , wherein forming the data line contact includes:
forming a conductive plug contacting the remaining portion of the conductive region; and forming the data line contact above and contacting the conductive plug.

14 . The method of claim 13 , wherein the conductive plug is a polysilicon plug and the data line contact includes tungsten.

15 . The method of claim 6 , wherein the shallow trench isolation region includes a dielectric nitride.

16 . A memory device comprising:
a memory cell having a storage element and an access device; a data line contact coupled to the access device of the memory cell; a cell contact coupled to the access device of the memory cell; a shallow trench isolation region adjacent to and contacting the data line contact; and a dielectric structure contacting the data line contact and the cell contact, the dielectric structure on and contacting the shallow trench isolation region and separating the data line contact from the cell contact.

17 . The memory device of claim 16 , wherein the dielectric structure is a non-oxide dielectric.

18 . The memory device of claim 17 , wherein the non-oxide dielectric includes one or more of a dielectric nitride or silicon carbide.

19 . The memory device of claim 16 , wherein the data line contact connects to a metallic data line.

20 . The memory device of claim 16 , wherein the access device is a transistor and the storage element is a capacitor.

Assignees

• Micron Technology Inc

Inventors

• Yao Chunhua
• Guo Song
• Yadav Vivek

Classifications

• H10W10/17

  formed using trench refilling with dielectric materials, e.g. shallow trench isolations · CPC title

• H10W10/014

  using trench refilling with dielectric materials, e.g. shallow trench isolations · CPC title

• H10B12/482

  Bit lines · CPC title

• H10B12/488

  Word lines · CPC title

• H10B12/48

  Data lines or contacts therefor · CPC title