III-V semiconductor device with interfacial layer

Patent metadata

Field	Value
Publication number	US-9691872-B2
Application number	US-201414341629-A
Country	US
Kind code	B2
Filing date	Jul 25, 2014
Priority date	Jul 25, 2013
Publication date	Jun 27, 2017
Grant date	Jun 27, 2017

Abstract

A semiconductor structure comprises a substrate including a III-V material, and a high-k interfacial layer overlaying the substrate. The interfacial layer includes a rare earth aluminate. The present disclosure also relates to an n-type FET device comprising the same, and a method for manufacturing the same.

First claim

What is claimed is:

1. A semiconductor structure comprising:
a substrate comprising a III-V material; and
a high-k interfacial layer overlaying the substrate, wherein the interfacial layer comprises a rare earth aluminate, and wherein the high-k interfacial layer has a top surface facing away from the substrate and a bottom surface facing toward the substrate, and wherein an aluminium content at the top surface is higher than at the bottom surface.

2. The semiconductor structure of claim 1 , further comprising a high-k dielectric layer overlying the interfacial layer.

3. The semiconductor structure of claim 2 , wherein an equivalent oxide thickness of the stack of the high-k interfacial layer and the high-k dielectric layer is below 1 nm.

4. The semiconductor structure of claim 3 , wherein the high-k interfacial layer comprises Gd x Al y O 3 , and wherein x is at most 1.0.

5. The semiconductor structure of claim 3 , wherein the high-k interfacial layer comprises Sc x Al y O 3 , and wherein y is at least 0.5.

6. The semiconductor structure of claim 2 , wherein the high-k dielectric layer includes one or more of HfO 2 , TiO 2 , or ZnO 2 .

7. The semiconductor structure of claim 2 , wherein the thickness of the high-k dielectric layer is from 0.5 to 2 nm.

8. The semiconductor structure of claim 2 , wherein a leakage current below 0.01 A/cm 2 is achieved at 1V.

9. The semiconductor structure of claim 1 , wherein the rare earth aluminate includes one or more of Gd x Al y O 3 , Sc x Al y O 3 , or La x Al y O 3 , wherein x is from 0.4 to 1.6, and wherein x+y=2.

10. The semiconductor structure of claim 9 , wherein x is from 0.4 to 1.5, and wherein x+y=2.

11. The semiconductor structure of claim 10 , wherein x is from 0.4 to 1.4, and wherein x+y=2.

12. The semiconductor structure of claim 1 , wherein the III-V material includes one or more of InP, In z Ga 1-z As, or Al z Ga 1-z As, and wherein z is from 0 to 1.

13. The semiconductor structure of claim 1 , wherein the thickness of the high-k interfacial layer is from 0.5 to 2 nm.

14. The semiconductor structure of claim 1 , wherein a sulphur-comprising compound is present at the interface between the substrate and the high-k interfacial layer.

15. An n-type FET device comprising a semiconductor structure according to claim 1 .

16. A method for manufacturing a semiconductor structure according to claim 1 comprising:
providing a substrate comprising a III-V material; and
depositing a high-k interfacial layer overlaying the substrate, wherein the interfacial layer comprises a rare earth aluminate, wherein the high-k interfacial layer has a top surface facing away from the substrate and a bottom surface facing toward the substrate, and wherein an aluminium content at the top surface is higher than at the bottom surface.

17. The semiconductor structure of claim 1 , wherein an interface between the substrate and the high-k interfacial layer has an interface defect density between 5*10 10 to 5*10 12 defects/cm 2 when measured at at least one energy level within a bandgap of the III-V material.

Assignees

• Imec Vzw
• Univ Leuven Kath

Inventors

• Lin Han Chung
• Nyns Laura
• Ivanov Tsvetan
• Van Dorp Dennis

Classifications

• H10P14/69391

  the material containing aluminium, e.g. Al2O3 · CPC title

• H10P14/6938

  the material containing at least one metal element, e.g. metal oxides, metal oxynitrides or metal oxycarbides · CPC title

• H10P14/69396

  the material containing at least one rare earth metal element, e.g. oxides of lanthanides, scandium or yttrium · CPC title

• H10D64/01358

  the insulator being formed after the semiconductor body, the semiconductor being a Group III-V material · CPC title

• H10D62/85

  being Group III-V materials, e.g. GaAs · CPC title