Vertical structure having an etch stop over portion of the source

Patent metadata

Field	Value
Publication number	US-9805968-B2
Application number	US-201715430614-A
Country	US
Kind code	B2
Filing date	Feb 13, 2017
Priority date	Feb 11, 2014
Publication date	Oct 31, 2017
Grant date	Oct 31, 2017

Abstract

According to an exemplary embodiment, a method of forming a semiconductor device is provided. The method includes: providing a vertical structure over a substrate; forming an etch stop layer over the vertical structure; forming an oxide layer over the etch stop layer; performing chemical mechanical polishing on the oxide layer and stopping on the etch stop layer; etching back the oxide layer and the etch stop layer to expose a sidewall of the vertical structure and to form an isolation layer; oxidizing the sidewall of the vertical structure and doping oxygen into the isolation layer by using a cluster oxygen doping treatment.

First claim

What is claimed is:

1. A vertical structure, comprising:
a source;
a channel over the source;
a drain over the channel;
an oxidized portion of an etch stop layer contacting the source; and
an oxide layer contacting the etch stop layer.

2. The vertical structure of claim 1 , wherein an oxygen concentration of the oxide layer has a box-like region with a tailing region.

3. The vertical structure of claim 2 , wherein the box-like region has a depth of about 1 nm to about 10 nm, and the oxygen concentration in the box-like region is about 10 20 /cm 3 to about 5*10 22 /cm 3 .

4. The vertical structure of claim 2 , wherein the tailing region has a depth of about 1 nm to about 10 nm, and the oxygen concentration in the tailing is about 10 19 /cm 3 to about 10 20 /cm 3 .

5. The vertical structure of claim 1 , wherein the oxidized portion of the etch stop layer is adjacent to a sidewall of the source and has a thickness gradient from top to bottom.

6. The vertical structure of claim 1 , wherein the source, the channel and the drain form a shape selecting from trapezoid, inverse-trapezoid and rectangle.

7. The vertical structure of claim 1 , wherein the oxide layer is doped with oxygen.

8. The vertical structure of claim 1 having a cross sectional shape of a trapezoid.

9. The semiconductor device of claim 8 , wherein the oxide is oxygen doped.

10. The semiconductor device of claim 8 , wherein a portion of the nitride layer adjacent the second portion comprises an oxidized nitride.

11. The semiconductor device of claim 8 , wherein an oxidized portion of the nitride layer adjacent to the sidewalls of the second portion has a thickness gradient.

12. The semiconductor device of claim 8 , wherein the semiconductor device has a cross-sectional shape of a trapezoid.

13. The semiconductor device of claim 8 , wherein a first portion of the nitride layer is adjacent the sidewalls the second portion of the source and above a first portion of the source in a direction parallel to an axis passing through the source the drain and the channel.

14. A semiconductor device comprising, comprising:
a vertical structure comprising a source over a substrate;
an oxide layer above a first portion of the source and not above a second portion of the source, the second portion adjacent to the vertical structure; and
a nitride layer between the oxide layer and a sidewall of the second portion of the source.

15. A vertical device, comprising:
a source, a drain, and a channel between the source and the drain;
an etch stop layer over a portion of the source; and
an oxide layer over the etch stop layer.

16. The vertical device of claim 15 , wherein the oxide layer is around a sidewall of the portion of the source.

17. The vertical device of claim 15 , wherein the oxide layer is oxygen doped.

18. The vertical device of claim 15 , wherein a portion of the etch stop layer between the oxide layer and the portion of the source has a thickness gradient.

19. The vertical device of claim 18 , wherein the portion of the etch stop layer is adjacent to a sidewall of the portion of the source.

20. The vertical device of claim 15 , wherein the vertical device has a cross-sectional shape of a trapezoid.

Assignees

• Taiwan Semiconductor Mfg Co Ltd

Inventors

• Lin Cheng-Tung
• Tsai Teng-Chun
• Wang Li-Ting
• Chen De-Fang
• Chen Bing-Hung
• Huang Huang-Yi
• Chang Hui-Cheng
• Lin Huan-Just
• Tsai Ming-Hsing

Classifications

• H10P30/224

  of a cluster, e.g. using a gas cluster ion beam · CPC title

• H10P95/064

  the removal being chemical etching · CPC title

• H10P95/062

  involving a dielectric removal step · CPC title

• H10P50/283

  by chemical means · CPC title

• H10P30/40

  into insulating materials · CPC title