Methods of forming embedded source/drain regions on finFET devices

Patent metadata

Field	Value
Publication number	US-9530869-B2
Application number	US-201514643409-A
Country	US
Kind code	B2
Filing date	Mar 10, 2015
Priority date	Mar 10, 2015
Publication date	Dec 27, 2016
Grant date	Dec 27, 2016

Abstract

One illustrative method disclosed herein includes, among other things, forming a layer of insulating material in the source/drain regions of the device, wherein the layer of insulating material has an upper surface that is substantially planar with an upper surface of a gate cap layer, recessing the layer of insulating material such that its recessed upper surface exposes a surface of the fin, performing another etching process to remove at least a portion of the fin and thereby define a recessed fin trench positioned above the recessed fin, and forming an epitaxial semiconductor material that is at least partially positioned in the recessed fin trench.

First claim

What is claimed:

1. A method of forming embedded source/drain regions on a FinFET device comprised of a fin, a gate structure positioned around a section of said fin and a gate cap layer positioned above said gate structure, the method comprising:
forming a sidewall spacer adjacent said gate structure;
after forming said sidewall spacer, forming a layer of insulating material adjacent said sidewall spacer and above portions of said fin positioned laterally outside said sidewall spacer, said layer of insulating material having an upper surface that is substantially planar with an upper surface of said gate cap layer;
performing a first recess etching process on said layer of insulating material to define a recessed layer of insulating material having a recessed upper surface, wherein at least an upper surface of said fin is exposed after said first recess etching process is completed;
performing at least one second etching process to remove at least a portion of said fin and thereby define a recessed fin and a recessed fin trench positioned above said recessed fin, said recessed fin trench having said recessed layer of insulating material located adjacent opposite sides of said recessed fin trench; and
performing at least one epitaxial deposition process to form at least one epitaxial semiconductor material that is at least partially positioned in said recessed fin trench.

2. The method of claim 1 , wherein said forming said layer of insulating material comprises:
depositing said layer of insulating material such that it has an as-deposited upper surface that is positioned above said upper surface of said gate cap layer; and
performing a planarization process on said layer of insulating material until the planarized upper surface of said layer of insulating material is substantially planar with said upper surface of said gate cap layer.

3. The method of claim 1 , wherein said layer of insulating material is comprised of silicon dioxide.

4. The method of claim 1 , wherein said performing said first recess etching process on said layer of insulating material comprises performing a timed, anisotropic etching process.

5. The method of claim 1 , wherein said performing said at least one second etching process comprises performing a single etching process that selectively removes a portion of said fin relative to surrounding materials.

6. The method of claim 1 , wherein said performing said at least one second etching process comprises performing a fin removal etching process that selectively removes a portion of said fin relative to surrounding materials and thereafter performing an insulating material removal etching process to remove a portion of said layer of insulating material.

7. The method of claim 6 , wherein said performing said at least one second etching process further comprises performing another fin removal etching process that selectively removes a portion of said fin relative to surrounding materials.

8. The method of claim 1 , wherein said recessed fin trench has a cross-sectional profile that is one of a substantially rectangular, substantially trapezoidal, rounded or a combination of any of the foregoing.

9. The method of claim 1 , wherein said at least one selective epitaxial semiconductor material is comprised of at least one of silicon, germanium, silicon-germanium or a III-V material.

10. The method of claim 1 , wherein said at least one selective epitaxial deposition process is performed such that a portion of said layer of insulating material adjacent an opening of said recessed fin trench is clear of said at least one epitaxial semiconductor material.

11. The method of claim 1 , wherein said at least one selective epitaxial deposition process is performed such that said at least one epitaxial semiconductor material overfills said recessed fin trench and such that a portion of said at least one epitaxial semiconductor material is positioned above said layer of insulating material located adjacent an opening of said recessed fin trench.

12. The method of claim 11 , wherein said portion of said at least one epitaxial semiconductor material positioned above said layer of insulating material located adjacent said opening of said recessed fin trench has one of a rounded or triangular shaped upper surface.

13. The method of claim 1 , wherein said performing said at least one second etching process to remove at least a portion of said fin and thereby define said recessed fin and said recessed fin trench positioned above said recessed fin comprises performing said at least one second etching process so as to remove substantially all of said fin positioned at a level above a level of an upper surface of a local isolation material positioned in a trench adjacent said fin.

14. The method of claim 1 , wherein said at least one selective epitaxial deposition process is performed such that said at least one epitaxial semiconductor material overfills said recessed fin trench and merges with an epitaxial material formed on an adjacent fin of said FinFET device.

15. The method of claim 1 , wherein said at least one selective epitaxial deposition process is performed such that said at least one epitaxial semiconductor material formed on said recessed fin trench does not merge with an epitaxial material formed on an adjacent fin of said FinFET device.

16. A method of forming embedded source/drain regions on a FinFET device comprised of a fin, a gate structure positioned around a section of said fin and a gate cap layer positioned above said gate structure, the method comprising:
forming a plurality of fin-formation trenches in a semiconductor substrate to thereby define a fin having an upper surface
forming a first layer of insulating material in said trenches adjacent said fin, said first layer of insulating material having an upper surface that exposes an upper portion of said fin;
performing at least one process operation to form a gate structure around a section of said upper portion of said fin and a gate cap layer positioned above said gate structure, wherein said gate structure is positioned above said upper surface of said first layer of insulating material;
forming a sidewall spacer adjacent said gate structure;
after forming said sidewall spacer, forming a second layer of insulating material adjacent said sidewall spacer and above portions of said fin positioned laterally outside said sidewall spacer, said second layer of insulating material having an upper surface that is substantially planar with an upper surface of said gate cap layer;
performing a first recess etching process on said second layer of insulating material to define a recessed second layer of insulating material having a recessed upper surface, wherein at least said upper surface of said fin is exposed after said first recess etching process is completed;
performing at least one second etching process to remove at least a portion of said fin and thereby define a recessed fin and a recessed fin trench positioned above said recessed fin, said recessed fin trench having at least said recessed second layer of insulating material located adjacent opposite sides of said recessed fin trench; and
performing at least one epitaxial deposition process to form at least one epitaxial semiconductor material that is at least partially positioned in said recessed fin trench.

17. The method of claim 16 , wherein said forming said second layer of insulating material, comprises:
depositing said second layer of insulating material such that it has an as-deposited upper surface that is positioned above said upper sur

Assignees

• Globalfoundries Inc

Inventors

• Akarvardar Murat Kerem
• Fronheiser Jody A
• Bentley Steven

Classifications

• H10P95/06

  Planarisation of inorganic insulating materials · CPC title

• H10P50/642

  Chemical etching · CPC title

• H10P50/283

  by chemical means · CPC title

• H10P14/69215

  the material being a silicon oxide, e.g. SiO2 · CPC title

• H10P14/27

  using selective deposition, e.g. simultaneous growth of monocrystalline and non-monocrystalline semiconductor materials · CPC title