NON-PLANAR SEMICONDUCTOR DEVICE HAVING GROUP III-V MATERIAL ACTIVE REGION WITH MULTI-DIELECTRIC GATE STACK

• US 20150221762A1
• Filed: 04/16/2015
• Published: 08/06/2015
• Est. Priority Date: 09/27/2012
• Status: Active Grant

• Current Assignee: Tahoe Research Limited (f/k/a Learndale Limited) (Vector Capital Corporation)
• Original Assignee: Benjamin Chu-Kung, Gilbert Dewey, Marko Radosavljevic, Niloy Mukherjee, Ravi Pillarisetty
• Inventors: Dewey, Gilbert, Radosavljevic, Marko, Pillarisetty, Ravi, Chu-Kung, Benjamin, Mukherjee, Niloy
• Granted Patent: US 9,343,574 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 99/00 Subject matter not provided for in other groups of this subclass
• CPC Class Codes: H01L 29/0665 the shape of the body defining a nanostructure nanotechnology per se B82B
• CPC Class Codes: H01L 29/0673 oriented parallel to a substrate
• CPC Class Codes: H01L 29/201 including two or more compounds , e.g. alloys H01L29/2006 takes precedence
• CPC Class Codes: H01L 29/205 in different semiconductor regions , e.g. heterojunctions
• CPC Class Codes: H01L 29/408 with an insulating layer with a particular dielectric or electrostatic property, e.g. with static charges or for controlling trapped charges or moving ions, or with a plate acting on the insulator potential or the insulator charges, e.g. for controlling charges effect or potential distribution in the insulating layer, or with a semi-insulating layer contacting directly the semiconductor surface
• CPC Class Codes: H01L 29/4236 within a trench, e.g. trench gate electrode, groove gate electrode
• CPC Class Codes: H01L 29/42364 characterised by the insulating layer, e.g. thickness or uniformity H01L29/42324 and H01L29/4234 take precedence
• CPC Class Codes: H01L 29/42392 fully surrounding the channel, e.g. gate-all-around
• CPC Class Codes: H01L 29/511 with a compositional variation, e.g. multilayer structures H01L29/516 takes precedence
• CPC Class Codes: H01L 29/512 the variation being parallel to the channel plane
• CPC Class Codes: H01L 29/513 the variation being perpendicular to the channel plane
• CPC Class Codes: H01L 29/517 the insulating material comprising a metallic compound, e.g. metal oxide, metal silicate H01L29/518 takes precedence
• CPC Class Codes: H01L 29/518 the insulating material containing nitrogen, e.g. nitride, oxynitride, nitrogen-doped material
• CPC Class Codes: H01L 29/66462 with a heterojunction interface channel or gate, e.g. HFET, HIGFET, SISFET, HJFET, HEMT
• CPC Class Codes: H01L 29/775 with one dimensional charge carrier gas channel, e.g. quantum wire FET
• CPC Class Codes: H01L 29/78 with field effect produced by an insulated gate H01L29/7725, H01L29/775, H01L29/778 take precedence
• 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
• CPC Class Codes: H01L 29/78696 characterised by the structure of the channel, e.g. multichannel, transverse or longitudinal shape, length or width, doping structure, or the overlap or alignment between the channel and the gate, the source or the drain, or the contacting structure of the channel H01L29/78612 takes precedence; transistors having a drain offset region or a lightly doped drain [LDD] H01L29/78621

Abstract

Non-planar semiconductor devices having group III-V material active regions with multi-dielectric gate stacks are described. For example, a semiconductor device includes a hetero-structure disposed above a substrate. The hetero-structure includes a three-dimensional group III-V material body with a channel region. A source and drain material region is disposed above the three-dimensional group III-V material body. A trench is disposed in the source and drain material region separating a source region from a drain region, and exposing at least a portion of the channel region. A gate stack is disposed in the trench and on the exposed portion of the channel region. The gate stack includes first and second dielectric layers and a gate electrode.

Claims

1. A semiconductor device, comprising:

a semiconductor material stack disposed above a substrate and comprising a three-dimensional group III-V material body with a channel region;

a source and drain material region disposed above the three-dimensional group III-V material body;

a trench disposed in the source and drain material region separating a source region from a drain region, the trench also disposed in the semiconductor material stack and completely exposing the channel region; and

a gate stack disposed in the trench and completely surrounding the channel region, the gate stack comprising;

a first dielectric layer conformal with the trench and disposed on outer portions, but not an inner portion, of the channel region;

a second, different, dielectric layer conformal with the first dielectric layer and disposed on the inner portion of the channel region; and

a gate electrode disposed on the second dielectric layer.

2. The semiconductor device of claim 1, wherein the second dielectric layer has a higher dielectric constant than the first dielectric layer.

3. The semiconductor device of claim 2, wherein the second dielectric layer has a dielectric constant greater than approximately 8 and the first dielectric layer has a dielectric constant approximately in the range of 4-8.

4. The semiconductor device of claim 2, wherein the second dielectric layer comprises a material selected from the group consisting of tantalum silicon oxide (TaSiO_x), aluminum oxide (AlO_x), hafnium oxide (HfO₂), zirconium oxide (ZrO₂), and lanthanum oxide (La₂O₃), and the first dielectric layer comprises a material selected from the group consisting of aluminum silicate (AlSiO_x), silicon oxynitride (SiON), silicon dioxide (SiO₂) and silicon nitride (Si₃N₄).

5. The semiconductor structure of claim 1, wherein the first dielectric layer has a thickness approximately in the range of 2-15 nanometers, and the second dielectric layer has a thickness approximately in the range of 0.5-3 nanometers.

6. A semiconductor device, comprising:

a vertical arrangement of a plurality of group III-V material nanowires disposed above a substrate;

a gate stack disposed on and completely surrounding channel regions of each of the group III-V material nanowires, the gate stack comprising;

a first dielectric layer disposed on outer portions, but not an inner portion, of each of the channel regions;

a second, different, dielectric layer conformal with the first dielectric layer and disposed on the inner portion of each of the channel regions; and

a gate electrode disposed on the second dielectric layer;

a semiconductor layer disposed between the substrate and the bottom-most group III-V material nanowire, wherein a bottom portion of the gate stack is disposed on the semiconductor layer; and

source and drain regions disposed in or on each of the group III-V material nanowires, on either side of the gate stack.

7. The semiconductor device of claim 6, wherein the second dielectric layer has a higher dielectric constant than the first dielectric layer.

8. The semiconductor device of claim 7, wherein the second dielectric layer has a dielectric constant greater than approximately 8 and the first dielectric layer has a dielectric constant approximately in the range of 4-8.

9. The semiconductor device of claim 7, wherein the second dielectric layer comprises a material selected from the group consisting of tantalum silicon oxide (TaSiO_x), aluminum oxide (AlO_x), hafnium oxide (HfO₂), zirconium oxide (ZrO₂), and lanthanum oxide (La₂O₃), and the first dielectric layer comprises a material selected from the group consisting of aluminum silicate (AlSiO_x), silicon oxynitride (SiON), silicon dioxide (SiO₂) and silicon nitride (Si₃N₄).

10. The semiconductor structure of claim 6, wherein the first dielectric layer has a thickness approximately in the range of 2-15 nanometers, and the second dielectric layer has a thickness approximately in the range of 0.5-3 nanometers.

11. A semiconductor device, comprising:

a semiconductor material stack disposed above a substrate and comprising a three-dimensional group III-V material body with a channel region;

a source and drain material region disposed above the three-dimensional group III-V material body;

a trench disposed in the source and drain material region separating a source region from a drain region, the trench also disposed in the semiconductor material stack and completely exposing the channel region; and

a gate stack disposed in the trench and on and completely surrounding the channel region, the gate stack comprising;

a first dielectric layer conformal with the trench and disposed on the exposed portion of the channel region;

a second, different, dielectric layer conformal with and disposed on the first dielectric layer, but not on the channel region; and

a gate electrode disposed on the second dielectric layer.

12. The semiconductor device of claim 11, wherein the second dielectric layer has a higher dielectric constant than the first dielectric layer.

13. The semiconductor device of claim 12, wherein the second dielectric layer has a dielectric constant greater than approximately 8 and the first dielectric layer has a dielectric constant approximately in the range of 4-8.

14. The semiconductor device of claim 12, wherein the second dielectric layer comprises a material selected from the group consisting of tantalum silicon oxide (TaSiO_x), aluminum oxide (AlO_x), hafnium oxide (HfO₂), zirconium oxide (ZrO₂), and lanthanum oxide (La₂O₃), and the first dielectric layer comprises a material selected from the group consisting of aluminum silicate (AlSiO_x), silicon oxynitride (SiON), silicon dioxide (SiO₂) and silicon nitride (Si₃N₄).

15. The semiconductor structure of claim 12, wherein the first dielectric layer has a thickness approximately in the range of 0.3-2 nanometers, and the second dielectric layer has a thickness approximately in the range of 0.5-3 nanometers.

16. A semiconductor device, comprising:

a vertical arrangement of a plurality of group III-V material nanowires disposed above a substrate;

a gate stack disposed on and completely surrounding channel regions of each of the group III-V material nanowires, the gate stack comprising;

a first dielectric layer disposed on each of the channel regions;

a second, different, dielectric layer conformal with the first dielectric layer and disposed on the first dielectric layer, but not on each of the channel regions; and

a gate electrode disposed on the second dielectric layer;

source and drain regions disposed in or on each of the group III-V material nanowires, on either side of the gate stack; and

a semiconductor layer disposed between the substrate and the bottom-most group III-V material nanowire, wherein a bottom portion of the gate stack is disposed on the semiconductor layer.

17. The semiconductor device of claim 16, wherein the second dielectric layer has a higher dielectric constant than the first dielectric layer.

18. The semiconductor device of claim 17, wherein the second dielectric layer has a dielectric constant greater than approximately 8 and the first dielectric layer has a dielectric constant approximately in the range of 4-8.

19. The semiconductor device of claim 17, wherein the second dielectric layer comprises a material selected from the group consisting of tantalum silicon oxide (TaSiO_x), aluminum oxide (AlO_x), hafnium oxide (HfO₂), zirconium oxide (ZrO₂), and lanthanum oxide (La₂O₃), and the first dielectric layer comprises a material selected from the group consisting of aluminum silicate (AlSiO_x), silicon oxynitride (SiON), silicon dioxide (SiO₂) and silicon nitride (Si₃N₄).

20. The semiconductor structure of claim 16, wherein the first dielectric layer has a thickness approximately in the range of 0.3-2 nanometers, and the second dielectric layer has a thickness approximately in the range of 0.5-3 nanometers.