Method for making a semiconductor device having a high-k gate dielectric

• US 20050048794A1
• Filed: 08/28/2003
• Published: 03/03/2005
• Est. Priority Date: 08/28/2003
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Chau, Robert S., Doczy, Mark L., Kavalieros, Jack, Brask, Justin K., Hareland, Scott A., Metz, Matthew V., Barnak, John P.
• Granted Patent: US 6,939,815 B2
• Time in Patent Office: Days
• US Class Current: 438/768
• CPC Class Codes: H01L 21/02052 Wet cleaning only H01L21/02085 takes precedence
• CPC Class Codes: H01L 21/02178 the material containing aluminium, e.g. Al2O3
• CPC Class Codes: H01L 21/02181 the material containing hafnium, e.g. HfO2
• CPC Class Codes: H01L 21/02244 of a metallic layer
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• CPC Class Codes: H01L 21/02337 treatment by exposure to a gas or vapour
• CPC Class Codes: H01L 21/0234 treatment by exposure to a plasma
• CPC Class Codes: H01L 21/28167 on single crystalline silicon, e.g. using a liquid, i.e. chemical oxidation
• CPC Class Codes: H01L 21/28194 by deposition, e.g. evaporation, ALD, CVD, sputtering, laser deposition H01L21/28202 takes precedence
• CPC Class Codes: H01L 21/3003 Hydrogenation or deuterisation, e.g. using atomic hydrogen from a plasma
• CPC Class Codes: H01L 21/31612 on a silicon body
• CPC Class Codes: H01L 21/31637 Deposition of Tantalum oxides, e.g. Ta2O5
• CPC Class Codes: H01L 21/31641 Deposition of Zirconium oxides, e.g. ZrO2
• CPC Class Codes: H01L 21/31645 Deposition of Hafnium oxides, e.g. HfO2
• CPC Class Codes: H01L 21/31683 of metallic layers, e.g. Al deposited on the body, e.g. formation of multi-layer insulating structures
• CPC Class Codes: H01L 21/31691 with perovskite structure
• 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

Abstract

A method for making a semiconductor device is described. That method comprises forming a metal oxide layer on a substrate, converting at least part of the metal oxide layer to a metal layer; and oxidizing the metal layer to generate a metal oxide high-k gate dielectric layer.

Claims

1. A method for making a semiconductor device comprising:

forming a metal oxide layer on a substrate;

converting at least part of the metal oxide layer to a metal layer; and

oxidizing the metal layer to generate a metal oxide high-k gate dielectric layer.

2. The method of claim 1 wherein the metal oxide layer is formed by atomic layer chemical vapor deposition, is between about 5 angstroms and about 40 angstroms thick, and comprises a material selected from the group consisting of hafnium oxide, hafnium silicon oxide, lanthanum oxide, zirconium oxide, zirconium silicon oxide, titanium oxide, tantalum oxide, barium strontium titanium oxide, barium titanium oxide, strontium titanium oxide, yttrium oxide, aluminum oxide, and lead scandium tantalum oxide.

3. The method of claim 2 further comprising forming a gate electrode on the metal oxide high-k gate dielectric layer and wherein the metal oxide high-k gate dielectric layer comprises a material selected from the group consisting of hafnium oxide, zirconium oxide, titanium oxide, and aluminum oxide.

4. The method of claim 3 wherein the gate electrode comprises polysilicon.

5. The method of claim 3 wherein the gate electrode is a metal gate electrode.

6. The method of claim 1 wherein at least part of the metal oxide layer is converted to a metal layer by exposing the metal oxide layer to hydrogen.

7. The method of claim 6 wherein at least part of the metal oxide layer is converted to a metal layer by exposing the metal oxide layer to a hydrogen based plasma.

8. The method of claim 6 wherein at least part of the metal oxide layer is converted to a metal layer by exposing the metal oxide layer to a hydrogen containing gas.

9. The method of claim 1 wherein the metal layer is oxidized to generate a metal oxide high-k gate dielectric layer by exposing the metal layer to an oxidizing agent.

10. The method of claim 9 wherein the oxidizing agent is a solution that comprises a compound selected from the group consisting of hydrogen peroxide, an organic peroxide, and ozone.

11. The method of claim 9 wherein the oxidizing agent is a gas that contains oxygen.

12. A method for making a semiconductor device comprising:

forming a metal oxide layer on a substrate, the metal oxide layer comprising halide impurities and a material selected from the group consisting of hafnium oxide, zirconium oxide, titanium oxide, and aluminum oxide;

reducing at least part of the metal oxide layer to a metal layer by exposing the metal oxide layer to hydrogen;

oxidizing the metal layer to generate a metal oxide high-k gate dielectric layer; and

forming a polysilicon based gate electrode on the metal oxide high-k gate dielectric layer.

13. The method of claim 12 wherein at least part of the metal oxide layer is reduced to a metal layer by exposing the metal oxide layer to a hydrogen containing gas.

14. The method of claim 12 wherein the metal layer is oxidized to generate a metal oxide high-k gate dielectric layer by exposing the metal layer to a solution that contains a peroxide.

15. The method of claim 12 wherein the metal layer is oxidized to generate a metal oxide high-k gate dielectric layer by exposing the metal layer to a gas that contains oxygen.

16. The method of claim 12 wherein the amount of halide impurities included in the metal oxide high-k gate dielectric layer is less than about twenty percent of the amount of halide impurities included in the metal oxide layer, and the amount of oxygen included in the metal oxide high-k gate dielectric layer exceeds the amount of oxygen included in the metal oxide layer.

17. The method of claim 12 wherein no oxidation occurs on the substrate, when the metal layer is oxidized to generate a metal oxide high-k gate dielectric layer.

18. A method for making a semiconductor device comprising:

forming a metal oxide layer on a substrate, the metal oxide layer comprising halide impurities and a material selected from the group consisting of hafnium oxide, zirconium oxide, titanium oxide, and aluminum oxide;

reducing substantially all of the metal oxide layer to a metal layer by exposing the metal oxide layer to a hydrogen containing gas;

oxidizing the metal layer to generate a metal oxide high-k gate dielectric layer by exposing the metal layer to a solution that comprises a compound selected from the group consisting of hydrogen peroxide, an organic peroxide, and ozone or by exposing the metal layer to a gas that contains oxygen; and

forming a polysilicon based gate electrode on the metal oxide high-k gate dielectric layer;

wherein the amount of halide impurities included in the metal oxide high-k gate dielectric layer is substantially less than the amount of halide impurities included in the metal oxide layer, and the amount of oxygen included in the metal oxide high-k gate dielectric layer significantly exceeds the amount of oxygen included in the metal oxide layer.

19. The method of claim 18 wherein an insignificant amount of oxidation occurs on the substrate, when the metal layer is oxidized to generate a metal oxide high-k gate dielectric layer.

20. The method of claim 19 wherein less than about 10 angstroms of oxide grows on the substrate, when the metal layer is oxidized to generate a metal oxide high-k gate dielectric layer.