Methods of forming fin cut regions by oxidizing fin portions

Patent metadata

Field	Value
Publication number	US-9847418-B1
Application number	US-201615219917-A
Country	US
Kind code	B1
Filing date	Jul 26, 2016
Priority date	Jul 26, 2016
Publication date	Dec 19, 2017
Grant date	Dec 19, 2017

Abstract

A method includes forming a fin on a substrate. A first liner is formed on the fin. A first dielectric layer is formed above the first liner. A patterned hard mask is formed above the first dielectric layer and has a fin cut opening defined therein. Portions of the first dielectric layer and the first liner disposed below the fin cut opening are removed to expose a portion of the fin. The patterned hard mask layer is removed. The exposed portion of the fin is oxidized to define a diffusion break in the fin.

First claim

What is claimed:

1. A method, comprising:
forming a fin on a substrate;
forming a first liner on said fin;
forming a first dielectric layer above said first liner;
patterning said first dielectric layer to define a fin cut opening therein, said fin cut opening exposing a portion of said first liner positioned above said fin;
removing portions of said first liner exposed by said fin cut opening to expose a portion of said fin; and
oxidizing said exposed portion of said fin to define a diffusion break in said fin, said diffusion break dividing said fin into first and second segments axially aligned with said diffusion break.

2. The method of claim 1 , further comprising:
forming a second liner on said diffusion break;
forming a second dielectric layer above said second liner;
recessing said first and second dielectric layers to expose an upper portion of said fin covered by said first liner and an upper portion of said diffusion break covered by said second liner; and
removing portions of said first and second liners exposed by recessing said first and second dielectric layers to expose first and second portions of said fin disposed adjacent said diffusion break and at least a portion of said diffusion break.

3. The method of claim 2 , wherein a cap layer is disposed above said fin, and the method further comprises removing said cap layer concurrently with removing said portions of said first and second liners exposed by recessing said first and second dielectric layers.

4. The method of claim 1 , wherein a cap layer is disposed above said fin, and the method further comprises removing a portion of said cap layer exposed by said fin cut opening concurrently with removing said portions of said first liner exposed by said fin cut opening.

5. The method of claim 1 , wherein said first dielectric layer comprises a hard mask.

6. The method of claim 1 , further comprising:
forming a second liner above said first dielectric layer and said diffusion break;
recessing said first dielectric layer; and
removing portions of said first and second liners exposed by recessing said first dielectric layer to expose first and second portions of said fin disposed adjacent said diffusion break and at least a portion of said diffusion break.

7. The method of claim 1 , wherein forming said first liner comprises forming sidewall spacers.

8. The method of claim 1 , further comprising:
recessing said first dielectric layer prior to oxidizing said exposed portion of said fin; and
forming a second liner on said diffusion break and on portions of said first liner exposed by recessing said first dielectric layer.

9. The method of claim 8 , wherein forming said second liner comprises forming sidewall spacers.

10. The method of claim 8 , further comprising:
forming a second dielectric layer above said fin and said diffusion break;
recessing said second dielectric layer to expose an upper portion of said fin covered by said first and second liners and an upper portion of said diffusion break covered by said second liner; and
removing portions of said first and second liners exposed by recessing said second dielectric layer to expose first and second portions of said fin disposed adjacent said diffusion break and at least a portion of said diffusion break.

11. The method of claim 10 , wherein a cap layer is disposed above said fin, and the method further comprises planarizing said second dielectric layer to expose said cap layer prior to recessing said second dielectric layer.

12. The method of claim 1 , further comprising:
recessing said first dielectric layer;
forming a second dielectric layer above remaining portions of said first liner and said diffusion break;
recessing said second dielectric layer to expose an upper portion of said fin covered by said first liner and an upper portion of said diffusion break; and
removing portions of said first liner exposed by recessing said second dielectric layer to expose first and second portions of said fin disposed adjacent said diffusion break.

13. The method of claim 1 , wherein forming said fin comprises forming trenches in said substrate to define an upper portion of said fin, forming said first liner comprises forming spacers on sidewalls of said upper portion, and the method further comprises etching said substrate in the presence of said spacers to deepen said trenches and define a lower portion of said fin below said upper portion.

14. The method of claim 13 , further comprising:
oxidizing a portion of said lower portion of said fin exposed by removing portions of said first dielectric layer disposed below said fin cut opening while said spacers cover said upper portion of said fin to define a lower portion of said diffusion break;
removing portions of said spacers disposed below said fin cut opening; and
oxidizing a portion of said upper portion of said fin exposed by removing said portions of said spacers to define an upper portion of said diffusion break above said lower portion of said diffusion break.

15. The method of claim 14 , further comprising:
forming a second liner above said first dielectric layer and said diffusion break;
recessing said first dielectric layer; and
removing portions of said first and second liners exposed by recessing said first dielectric layer to expose first and second portions of said fin disposed adjacent said diffusion break and at least a portion of said diffusion break.

16. The method of claim 15 , further comprising:
recessing said first dielectric layer prior to oxidizing said exposed portion of said fin;
forming a second liner on said diffusion break and on portions of said first liner exposed by recessing said first dielectric layer;
forming a second dielectric layer above said fin and said diffusion break;
recessing said second dielectric layer to expose an upper portion of said fin covered by said first and second liners and an upper portion of said diffusion break covered by said second liner; and
removing portions of said first and second liners exposed by recessing said second dielectric layer to expose first and second portions of said fin disposed adjacent said diffusion break and at least a portion of said diffusion break.

17. The method of claim 1 , wherein said fin comprises a strained material.

18. A method, comprising:
forming a fin on a substrate, wherein a cap layer is disposed on a top surface of said fin;
forming a first spacer on said fin;
forming a first dielectric layer above said fin;
patterning said first dielectric layer to define a fin cut opening therein, said fin cut opening exposing a portion of said cap layer and said first spacer positioned above said fin;
removing portions of said cap layer and said first spacer exposed by said fin cut opening to expose a portion of said fin;
oxidizing said exposed portion of said fin to define a diffusion break in said fin;
forming a liner on said diffusion break;
forming a second dielectric layer above said diffusion break;
exposing an upper portion of said fin covered by said cap layer and said first spacer and an upper portion of said diffusion break covered by said liner;
removing said cap layer and a portion of said first spacer disposed on said upper portion of said fin; and
removing a portion of said liner disposed on said upper portion of said diffusion break.

19. The method of claim 18 , wherein said liner comprises a second spacer.

20. The method of claim 19 , wherein forming said liner comprises forming said second

Assignees

• Globalfoundries Inc

Inventors

• Lim Kwan-Yong
• Sung Min Gyu
• Park Chanro

Classifications

• H10D30/024 Primary

  of fin field-effect transistors [FinFET] · CPC title

• H01L29/7848 Primary

  Electricity · mapped topic

• H01L29/66795

  Electricity · mapped topic

• H01L29/6656

  Electricity · mapped topic

• H01L29/6653

  Electricity · mapped topic