Finned semiconductor device with oxygen diffusion barrier regions, and related fabrication methods

• US 8,354,719 B2
• Filed: 02/18/2010
• Issued: 01/15/2013
• Est. Priority Date: 02/18/2010
• Status: Active Grant

• Current Assignee: Alsephina Innovations Inc. (Quarterhill Inc. (f/k/a Wi-LAN Inc.))
• Original Assignee: GlobalFoundries, Inc.
• Inventors: Choi, Kisik, Miller, Robert J.
• Primary Examiner(s): Richards, N Drew
• Assistant Examiner(s): SINGAL, ANKUSH K
• Application Number:
  US12/708,213
• Publication Number:
  US 20110198696A1
• Time in Patent Office: 1,062 Days
• Field of Search: 257/347
• US Class Current: 257/347
• CPC Class Codes: H01L 21/76229 Concurrent filling of a plurality of trenches having a different trench shape or dimension, e.g. rectangular and V-shaped trenches, wide and narrow trenches, shallow and deep trenches
• CPC Class Codes: H01L 29/66545 using a dummy, i.e. replacement gate in a process wherein at least a part of the final gate is self aligned to the dummy gate
• CPC Class Codes: H01L 29/66795 with a horizontal current flow in a vertical sidewall of a semiconductor body, e.g. FinFET, MuGFET
• CPC Class Codes: H01L 29/785 having a channel with a horizontal current flow in a vertical sidewall of a semiconductor body, e.g. FinFET, MuGFET

Abstract

A semiconductor device and related fabrication methods are provided. One exemplary fabrication method forms a fin arrangement overlying an oxide layer, where the fin arrangement includes one or more semiconductor fin structures. The method continues by nitriding exposed portions of the oxide layer without nitriding the one or more semiconductor fin structures, resulting in nitrided portions of the oxide layer. Thereafter, a gate structure is formed transversely overlying the fin arrangement, and overlying the exposed portions of the oxide layer. The nitrided portions of the oxide layer substantially inhibit diffusion of oxygen from the oxide layer into the gate structure.

Claims

1. A method of fabricating a semiconductor device, the method comprising:

forming a fin arrangement overlying a substrate that contains regions of oxide material, the fin arrangement comprising one or more semiconductor fin structures;

creating an oxygen diffusion barrier in the substrate;

thereafter, conformally forming a layer of insulating material overlying the fin arrangement and overlying and in direct contact with the oxygen diffusion barrier;

conformally forming a layer of metal material overlying the layer of insulating material; and

etching the layer of insulating material and the layer of metal material to form a gate structure transversely overlying the fin arrangement, and overlying the oxygen diffusion barrier, wherein the oxygen diffusion barrier substantially inhibits diffusion of oxygen from the oxide material into the gate structure.

2. The method of claim 1, wherein the oxygen diffusion barrier has an upper surface, and wherein conformally forming a layer of insulating material overlying the fin arrangement and overlying and in direct contact with the oxygen diffusion barrier comprises completely covering the upper surface of the oxygen diffusion barrier with the layer of insulating material.

3. The method of claim 1, wherein the fin arrangement comprises adjacent semiconductor fin structures, and wherein conformally forming a layer of metal material overlying the layer of insulating material comprises forming a portion of the layer of metal material between the adjacent semiconductor fin structures.

4. The method of claim 1, further comprising:

forming a cap on each semiconductor fin structure;

forming spacers adjacent sidewalls of each semiconductor fin structure and each cap thereon to define exposed portions of the oxide material; and

nitriding the exposed portions of the oxide material without nitriding the one or more semiconductor fin structures, resulting in nitrided portions of the oxide material.

5. The method of claim 1, wherein the fin arrangement comprises adjacent semiconductor fin structures, wherein conformally forming a layer of metal material overlying the layer of insulating material comprises forming a portion of the layer of metal material between the adjacent semiconductor fin structures, wherein the method further comprises forming a layer of conductive material overlying the layer of metal material, and wherein etching comprises etching the layer of conductive material to form the gate structure transversely overlying the fin arrangement.

6. The method of claim 1, wherein conformally forming a layer of metal material overlying the layer of insulating material comprises forming a portion of the layer of metal material between portions of the layer of insulating material.

7. The method of claim 1, wherein conformally forming a layer of metal material comprises conformally forming a layer of metal material directly in contact with the layer of insulating material.

8. The method of claim 5, wherein conformally forming a layer of conductive material overlying the layer of metal material comprises forming a portion of the layer of conductive material between the adjacent semiconductor fin structures.

9. A method of fabricating a semiconductor device, the method comprising:

providing a semiconductor-on-insulator substrate having an oxide insulator layer and a layer of semiconductor material overlying the oxide insulator layer;

forming fin structures from the layer of semiconductor material, each of the fin structures extending above an exposed upper surface of the oxide insulator layer;

thereafter, treating exposed portions of the oxide insulator layer to create oxygen diffusion barrier regions near the exposed upper surface of the oxide insulator layer;

thereafter, forming a layer of insulating material overlying the fin structures and overlying and in direct contact with the oxygen diffusion barrier regions;

forming a layer of metal material overlying the layer of insulating material; and

etching the layer of insulating material and the layer of metal material to form a gate structure transversely overlying the fin structures, and overlying the oxygen diffusion barrier regions, wherein the oxygen diffusion barrier regions substantially inhibit diffusion of oxygen from the oxide insulator layer into the gate structure.

10. The method of claim 9, wherein each oxygen diffusion barrier region has an upper surface, and wherein forming a layer of insulating material overlying the fin structures and overlying and in direct contact with the oxygen diffusion barrier regions comprises completely covering the upper surfaces of the oxygen diffusion barrier regions with the layer of insulating material.

11. The method of claim 9, wherein fin structures include adjacent fin structures, and wherein forming a layer of metal material overlying the layer of insulating material comprises forming a portion of the layer of metal material between the adjacent fin structures.

12. The method of claim 9, further comprising:

forming a cap on each fin structure;

forming nitride spacers adjacent sidewalls of each fin structure and each cap thereon, wherein forming the nitride spacers occurs before treating the exposed portions of the oxide insulator layer.

13. The method of claim 9, wherein the fin structures include adjacent fin structures, wherein forming a layer of metal material overlying the layer of insulating material comprises forming a portion of the layer of metal material between the adjacent fin structures, wherein the method further comprises forming a layer of conductive material overlying the layer of metal material, and wherein etching comprises etching the layer of conductive material to form the gate structure transversely overlying the fin structures.

14. The method of claim 9, wherein forming a layer of metal material overlying the layer of insulating material comprises forming a portion of the layer of metal material between portions of the layer of insulating material.

15. The method of claim 13, wherein forming a layer of conductive material overlying the layer of metal material comprises forming a portion of the layer of conductive material between the adjacent fin structures.

16. A semiconductor device structure comprising:

a layer of oxide insulation material having an upper surface;

semiconductor fin structures formed overlying the layer of oxide insulation material;

a gate structure transversely formed overlying the semiconductor fin structures such that base sections of the gate structure overlie the upper surface between adjacent semiconductor fin structures, and wherein the base sections of the gate structure include a layer of insulating material and a layer of metal material overlying the layer of insulating material; and

oxygen diffusion barrier regions of the oxide insulation material, located near the upper surface and adjacent and in direct contact with the layer of insulating material of the base sections of the gate structures, wherein the oxygen diffusion barrier regions substantially inhibit diffusion of oxygen from the layer of oxide insulation material into the base sections of the gate structure.

17. The semiconductor device structure of claim 16, wherein the base sections of the gate structure include a layer of conductive material overlying the layer of metal material.

18. The semiconductor device structure of claim 16, wherein the layer of insulating material is interposed between each semiconductor fin structure and the layer of metal material to prevent contact therebetween, and wherein the layer of insulating material is interposed between the oxygen diffusion barrier regions and the layer of metal material to prevent contact therebetween.

19. The semiconductor device structure of claim 16, wherein the oxygen diffusion barrier regions comprise implant regions having ions of a nitrogen-containing species implanted therein.

20. The semiconductor device structure of claim 16, wherein:

the layer of oxide insulation material is a layer of a semiconductor-on-insulator (SOI) substrate; and

the semiconductor fin structures are formed from a semiconductor layer of the SOI substrate.

21. The semiconductor device structure of claim 20, wherein:

the SOI substrate comprises a nitrided upper region of the oxide insulation material; and

the oxygen diffusion barrier regions are formed from the nitrided upper region.

22. A semiconductor device structure comprising:

a substrate of semiconductor material;

semiconductor fin structures formed from the semiconductor material;

oxide isolation regions between the semiconductor fin structures;

a gate structure transversely formed overlying the semiconductor fin structures, wherein the gate structure includes a layer of insulating material and a layer of metal material overlying the layer of insulating material, and wherein portions of the layer of insulating material and portions of the layer of metal material are located between the semiconductor fin structures; and

oxygen diffusion barrier regions of the oxide isolation regions, wherein the oxygen diffusion barrier regions substantially inhibit diffusion of oxygen from the oxide isolation regions into the gate structure.

23. The semiconductor device structure of claim 22, wherein the oxygen diffusion barrier regions are in direct contact with the layer of insulating material of the gate structure.

24. A method of fabricating a semiconductor device, the method comprising:

providing a semiconductor-on-insulator substrate having an oxide insulator layer, a layer of semiconductor material overlying the oxide insulator layer, and an oxygen diffusion barrier between the oxide insulation layer and the layer of semiconductor material;

forming fin structures from the layer of semiconductor material;

thereafter, forming a layer of insulating material overlying the fin structures and overlying and in direct contact with the oxygen diffusion barrier;

forming a layer of metal material overlying the layer of insulating material; and

etching the layer of insulating material and the layer of metal material to form a gate structure transversely overlying the fin structures, and overlying the oxygen diffusion barrier, wherein the oxygen diffusion barrier substantially inhibits diffusion of oxygen from the oxide insulator layer into the gate structure.

25. The method of claim 24, wherein the fin structures comprise adjacent fin structures, and wherein forming a layer of metal material overlying the layer of insulating material comprises forming a portion of the layer of metal material between the adjacent fin structures.

26. The method of claim 24 wherein the oxygen diffusion barrier has an upper surface, and wherein forming a layer of insulating material overlying the fin structures and overlying and in direct contact with the oxygen diffusion barrier comprises completely covering the upper surfaces of the oxygen diffusion barrier with the layer of insulating material.