Method for forming roughened surface

• US 7,923,382 B2
• Filed: 02/10/2009
• Issued: 04/12/2011
• Est. Priority Date: 04/28/2006
• Status: Active Grant

• Current Assignee: ASM International NV
• Original Assignee: ASM International NV
• Inventors: Huotari, Hannu, Haukka, Suvi
• Primary Examiner(s): LE, DUNG ANH
• Application Number:
  US12/368,845
• Publication Number:
  US 20090246931A1
• Time in Patent Office: 791 Days
• Field of Search: 438782-785, 438/680, 438/795, 977/742, 977/773
• US Class Current: 438/785
• CPC Class Codes: H01L 21/32051 Deposition of metallic or metal-silicide layers
• CPC Class Codes: H01L 28/84 being a rough surface, e.g. using hemispherical grains
• CPC Class Codes: H10B 12/033 the capacitor extending over the transistor
• CPC Class Codes: Y10S 977/742 Carbon nanotubes, CNTs
• CPC Class Codes: Y10S 977/773 Nanoparticle, i.e. structure having three dimensions of 100 nm or less

Abstract

Methods of forming a roughened metal surface on a substrate are provided, along with structures comprising such roughened surfaces. In preferred embodiments roughened surfaces are formed by selectively depositing metal or metal oxide on a substrate surface to form discrete, three-dimensional islands. Selective deposition may be obtained, for example, by modifying process conditions to cause metal agglomeration or by treating the substrate surface to provide a limited number of discontinuous reactive sites. The roughened metal surface may be used, for example, in the manufacture of integrated circuits.

Claims

1. A method for forming a roughened surface on a substrate, comprising:

providing the substrate in a reaction space with a first surface having an initial surface termination;

forming a discontinuous surface termination on the substrate;

forming catalyst nanoparticles on the surface of said substrate by atomic layer deposition (ALD); and

depositing carbon nanotubes on said catalyst nanoparticles.

2. The method of claim 1, wherein forming catalyst nanoparticles by ALD comprises depositing metal oxide and subsequently reducing said metal oxide to elemental metal.

3. The method of claim 1, wherein said catalyst nanoparticles comprise metal oxide.

4. The method of claim 2, wherein the metal oxide is reduced at a temperature at which agglomeration occurs.

5. The method of claim 1, wherein the substrate has a surface comprising SiO₂.

6. The method of claim 1, wherein the nanoparticles comprise one or more metals selected from the group consisting of Cu, Ni, Fe, Co, Zn, Ru, Rh, Pd, Ag, Re, Os, Ir, Pt, Mo and W.

7. The method of claim 1, wherein forming the discontinuous surface termination comprises contacting the substrate with a deposition enhancing reagent to modify a portion of reactive surface sites on the substrate.

8. The method of claim 7, wherein the deposition enhancing reagent is a gaseous halide or metalorganic compound.

9. The method of claim 8, wherein the deposition enhancing reagent is a halide selected from the group consisting of hydrogen halides and metal halides.

10. The method of claim 8, wherein the deposition enhancing agent is a halide selected from the group consisting of HCl, AlCl₃, HfCl₄ and SiCl₄.

11. The method of claim 8, wherein the metalorganic compound is selected from the group consisting of trimethylaluminum, tetrakis(ethylmethyl)aminohafnium, tetrakis(dimethyl)aminohafnium, tetrakis(diethyl)aminohafnium, tetrakis(ethylmethyl)aminozirconium, tetrakis(dimethyl)aminozirconium and tetrakis(diethyl)aminozirconium.

12. The method of claim 8, wherein after contacting the substrate with a gaseous halide or metalorganic compound, halide or metalorganic surface terminations are present at a concentration between about 0.001 terminations/nm² to 10 terminations/nm².

13. The method of claim 8, wherein after contacting the substrate with a gaseous halide or metalorganic compound, halide or metalorganic surface terminations are present at a concentration between about 0.1 terminations/nm² to 1.5 terminations/nm².

14. The method of claim 4, wherein the temperature at which the metal oxide is reduced is between 350°

C. and 650°

C.

15. The method of claim 4, wherein reducing comprises exposing the metal oxide to a reducing agent selected from the group consisting of alcohols (—

OH), aldehydes (—

CHO) and carboxylic acids (—

COOH).

16. The method of claim 1, further comprising forming a material over the nanoparticles and carbon nanotubes.

17. The method of claim 16, wherein the material comprises an insulating material.

18. The method of claim 17, wherein the insulating material comprises an oxide.

19. The method of claim 18, wherein the insulating material comprises a high-k material.