FINNED SEMICONDUCTOR DEVICE WITH OXYGEN DIFFUSION BARRIER REGIONS, AND RELATED FABRICATION METHODS

• US 20110198696A1
• Filed: 02/18/2010
• Published: 08/18/2011
• 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: Miller, Robert J., CHOI, Kisik
• Granted Patent: US 8,354,719 B2
• Time in Patent Office: Days
• 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; and

thereafter, forming 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 layer into the gate structure.

2. The method of claim 1, wherein creating the oxygen diffusion barrier comprises nitriding exposed portions of the oxide material without nitriding the one or more semiconductor fin structures, resulting in nitrided portions of the oxide material.

3. The method of claim 2, wherein forming the gate structure comprises:

forming a layer of insulating material overlying the fin arrangement and the nitrided portions of the oxide material; and

forming a layer of metal material overlying the layer of insulating material, wherein the nitrided portions of the oxide material substantially inhibit diffusion of oxygen from the oxide material into the layer of insulating material.

4. The method of claim 2, further comprising forming spacers adjacent sidewalls of the one or more semiconductor fin structures, wherein forming the spacers occurs before nitriding the exposed portions of the oxide material.

5. The method of claim 4, wherein nitriding the exposed portions of the oxide material comprises:

exposing the oxide material to a nitrogen-containing gas; and

performing a plasma nitridation process to incorporate nitrogen into the oxide material.

6. The method of claim 4, wherein nitriding the exposed portions of the oxide material comprises:

exposing the oxide material to a nitrogen-containing gas; and

performing a thermal nitridation process to incorporate nitrogen into the oxide material.

7. The method of claim 1, wherein:

the fin arrangement comprises hard mask material at ends of the one or more semiconductor fin structures; and

creating the oxygen diffusion barrier comprises implanting ions of a nitrogen-containing species into the oxide material, using the hard mask material as an ion implantation mask.

8. The method of claim 1, wherein the regions of oxide material are formed after forming the fin arrangement.

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; and

thereafter, forming 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 treating the exposed portions of the oxide insulator layer comprises nitriding the exposed portions of the oxide insulator layer without nitriding the fin structures.

11. The method of claim 9, wherein:

the gate structure comprises a layer of high-k dielectric material and a layer of metal material overlying the layer of high-k dielectric material; and

the oxygen diffusion barrier regions substantially inhibit diffusion of oxygen from the oxide insulator layer into the layer of high-k dielectric material.

12. The method of claim 9, further comprising forming nitride spacers adjacent sidewalls of the fin structures, wherein forming the nitride spacers occurs before treating the exposed portions of the oxide insulator layer.

13. The method of claim 12, wherein treating the exposed portions of the oxide insulator layer comprises:

exposing the oxide insulator layer to a nitrogen-containing gas; and

performing a plasma nitridation process to incorporate nitrogen into the oxide insulator layer.

14. The method of claim 12, wherein treating the exposed portions of the oxide insulator layer comprises:

exposing the oxide insulator layer to a nitrogen-containing gas; and

performing a thermal nitridation process to incorporate nitrogen into the oxide insulator layer.

15. The method of claim 9, wherein:

each of the fin structures includes a hard mask cap at its upper end; and

treating the exposed portions of the oxide insulator layer comprises implanting ions of a nitrogen-containing species into the oxide insulator layer, using the hard mask caps and the fin structures as an ion implantation mask.

16. A semiconductor device structure comprising:

a layer of oxide insulation material having an upper surface;

a plurality of 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

oxygen diffusion barrier regions of the oxide insulation material, located near the upper surface and adjacent 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 oxygen diffusion barrier regions comprise nitrided regions of the oxide insulation material.

18. The semiconductor device structure of claim 17, wherein the nitrided regions comprise plasma-nitrided regions.

19. The semiconductor device structure of claim 17, wherein the nitrided regions comprise thermally-nitrided regions.

20. 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.

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

22. The semiconductor device structure of claim 21, 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.

23. A semiconductor device structure comprising:

a substrate of semiconductor material;

a plurality of 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; 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.

24. The semiconductor device structure of claim 23, wherein the oxygen diffusion barrier regions comprise nitrided regions of the oxide isolation regions.

25. 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; and

thereafter, forming 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.

26. The method of claim 25, further comprising forming the oxygen diffusion barrier by nitriding a portion of the oxide insulator layer.