Method of forming a metal oxide dielectric

• US 7,326,656 B2
• Filed: 02/24/2006
• Issued: 02/05/2008
• Est. Priority Date: 09/30/2004
• Status: Active Grant

• Current Assignee: Tahoe Research Limited (f/k/a Learndale Limited) (Vector Capital Corporation)
• Original Assignee: Intel Corporation
• Inventors: Shah, Uday, Chau, Robert S., Doyle, Brian S., Brask, Justin K., Doczy, Mark, Kavalleros, Jack
• Primary Examiner(s): Le; Thao X.
• Assistant Examiner(s): Ingham; John C
• Application Number:
  US11/362,453
• Publication Number:
  US 20060138553A1
• Time in Patent Office: 711 Days
• Field of Search: 438/773, 438/785, 438/59, 438/680, 438/778, 257/E21.442
• US Class Current: 438/785
• CPC Class Codes: H01L 21/845 including field-effect transistors with a horizontal current flow in a vertical sidewall of a semiconductor body, e.g. FinFET, MuGFET
• CPC Class Codes: H01L 27/1211 combined with field-effect transistors with a horizontal current flow in a vertical sidewall of a semiconductor body, e.g. FinFET, MuGFET
• CPC Class Codes: H01L 29/0673 oriented parallel to a substrate
• CPC Class Codes: H01L 29/41791 for transistors with a horizontal current flow in a vertical sidewall, e.g. FinFET, MuGFET
• CPC Class Codes: H01L 29/66439 with a one- or zero-dimensional channel, e.g. quantum wire FET, in-plane gate transistor [IPG], single electron transistor [SET], striped channel transistor, Coulomb blockade transistor with an active layer made of a group 13/15 material H01L29/66469
• 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
• CPC Class Codes: Y10S 438/926 Dummy metallization
• CPC Class Codes: Y10S 438/974 Substrate surface preparation

Abstract

A semiconductor device comprising a semiconductor body having a top surface and a first and second laterally opposite sidewalls as formed on an insulating substrate is claimed. A gate dielectric is formed on the top surface of the semiconductor body and on the first and second laterally opposite sidewalls of the semiconductor body. A gate electrode is then formed on the gate dielectric on the top surface of the semiconductor body and adjacent to the gate dielectric on the first and second laterally opposite sidewalls of the semiconductor body. The gate electrode comprises a metal film formed directly adjacent to the gate dielectric layer. A pair of source and drain regions are then formed in the semiconductor body on opposite sides of the gate electrode.

Claims

1. A method of forming a metal oxide dielectric layer comprising:

exposing a silicon surface to a solution which makes said silicon surface hydrophilic;

exposing said hydrophilic silicon surface to a precursor comprising a metal halide;

reacting said metal halide with said hydrophilic silicon surface; and

treating said metal halide terminated silicon surface to form a metal oxide dielectric.

2. The method of claim 1 wherein said hydrophilic silicon surface comprises an OH terminated silicon atom.

3. The method of claim 1 wherein said solution comprises hydrogen peroxide.

4. The method of claim 3 wherein said solution comprises between 5-10% hydrogen peroxide by volume in water.

5. The method of claim 1 wherein said metal oxide dielectric is selected from the group consisting of hafnium oxide, aluminum oxide, zirconium oxide, lanthanum oxide, and lanthanum aluminum oxide.

6. The method of claim 5 wherein said metal oxide dielectric comprise hafnium oxide.

7. The method of claim 6 wherein said metal halide comprises hafnium tetrachloride (HfCl₄).

8. A method of forming a high dielectric constant film on a silicon surface comprising:

removing a silicon oxide film from a silicon surface with an aqueous HF solution to generate a hydrophobic silicon hydride surface;

treating said hydrophobic silicon hydride surface with a solution comprising hydrogen peroxide to convert said hydrophobic silicon hydride surface to a hydrophilic silicon hydroxide surface;

exposing said hydrophilic silicon hydroxide surface to a metal halide to form a metal halide terminated silicon surface; and

exposing said metal halide terminated silicon surface to water vapor to form a metal oxide dielectric film on said silicon surface.

9. The method of claim of claim 8 wherein said aqueous HF solution comprises approximately 1-2% HF by volume in water.

10. The method of claim 8 wherein said solution comprising hydrogen perioxide comprises 5-10% by weight of unstabilized hydrogen peroxide in water.

11. The method of claim 8 wherein said metal halide is selected from the group consisting of HfCl₄, ZrCl₄ and LaCl₃.

12. The method of claim 8 wherein said hydrophilic silicon hydroxide surface is exposed to a metal halide at a temperature between 350-450°

C.

13. The method of claim 8 further comprising after forming said metal oxide dielectric, exposing said metal oxide dielectric to said metal halide a second time and exposing said metal oxide to said water vapor a second time.

14. A method of forming a metal oxide dielectric layer on a semiconductor surface comprising:

converting a semiconductor surface into a hydrophilic semiconductor surface;

exposing said hydrophilic semiconductor surface to a precursor comprising a metal halide;

reacting said metal halide with said hydrophilic semiconductor surface to form a metal halide terminated semiconductor surface; and

treating said metal halide terminated semiconductor surface to form a metal oxide dielectric film on said semiconductor surface.

15. The method of claim 14 further comprising prior to converting said semiconductor surface to a hydrophilic surface, removing a film from said semiconductor surface, wherein said film removal process generates a hydrophobic semiconductor surface.

16. The method of claim 15 wherein said film is removed with a solution comprising HF.

17. The method of claim 14 wherein said converting said semiconductor surface to a hydrophilic semiconductor surface comprises exposing said semiconductor surface to a solution comprising hydrogen peroxide.

18. The method of claim 14 wherein said metal oxide dielectric is selected from the group consisting of hafnium oxide, aluminum oxide, zirconium oxide, lanthanum oxide and lanthanum aluminum oxide.

19. The method of claim 14 wherein said semiconductor surface is a selected from the group consisting of silicon, germanium, SiGe, GaAs, InSb, GaP, GaSb.