Method to restore hydrophobicity in dielectric films and materials

• US 7,029,826 B2
• Filed: 06/19/2001
• Issued: 04/18/2006
• Est. Priority Date: 06/23/2000
• Status: Expired due to Fees

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Thomas, Michael, Hacker, Nigel P., Drage, James S.
• Primary Examiner(s): McPherson, John A.
• Assistant Examiner(s): Chacko-Davis, Deborah
• Application Number:
  US10/312,295
• Publication Number:
  US 20040013858A1
• Time in Patent Office: 1,764 Days
• Field of Search: 430/311, 430/314, 430/316, 438/447
• US Class Current: 430/311
• CPC Class Codes: H01L 21/02063 the processing being the formation of vias or contact holes
• CPC Class Codes: H01L 21/02126 the material containing Si, O, and at least one of H, N, C, F, or other non-metal elements, e.g. SiOC, SiOC:H or SiONC
• CPC Class Codes: H01L 21/02203 the layer being porous
• CPC Class Codes: H01L 21/02216 the compound being a molecule comprising at least one silicon-oxygen bond and the compound having hydrogen or an organic group attached to the silicon or oxygen, e.g. a siloxane
• CPC Class Codes: H01L 21/02282 liquid deposition, e.g. spin-coating, sol-gel techniques, spray coating
• CPC Class Codes: H01L 21/02304 formation of intermediate layers, e.g. buffer layers, layers to improve adhesion, lattice match or diffusion barriers
• 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 21/02343 treatment by exposure to a liquid
• CPC Class Codes: H01L 21/02359 treatment to change the surface groups of the insulating layer
• CPC Class Codes: H01L 21/02362 formation of intermediate layers, e.g. capping layers or diffusion barriers
• CPC Class Codes: H01L 21/3105 After-treatment
• CPC Class Codes: H01L 21/31058 of organic layers
• CPC Class Codes: H01L 21/3122 layers comprising polysiloxane compounds
• CPC Class Codes: H01L 21/31695 Deposition of porous oxides or porous glassy oxides or oxide based porous glass
• CPC Class Codes: H01L 21/76814 post-treatment or after-treatment, e.g. cleaning or removal of oxides on underlying conductors
• CPC Class Codes: H01L 21/7682 the dielectric comprising air gaps
• CPC Class Codes: H01L 21/76826 by contacting the layer with gases, liquids or plasmas
• CPC Class Codes: H01L 21/76831 in via holes or trenches, e.g. non-conductive sidewall liners
• CPC Class Codes: Y10T 428/24802 Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]

Abstract

Silica dielectric films, whether nanoporous foamed silica dielectrics or nonporous silica dielectrics are readily damaged by fabrication methods and reagents that reduce or remove hydrophobic properties from the dielectric surface. The invention provides for methods of imparting hydrophobic properties to such damaged silica dielectric films present on a substrate. The invention also provides plasma-based methods for imparting hydrophobicity to both new and damaged silica dielectric films. Semiconductor devices prepared by the inventive processes are also provided.

Claims

1. A method of imparting hydrophobic properties to a damaged silica dielectric film present on a substrate, wherein said dielectric film has been contacted with at least one etchant or ashing reagent in such a way as to substantially damage or remove previously existing hydrophobicity of said dielectric film, the method comprising

(a) contacting the damaged silica dielectric film with a surface modification composition at a concentration and for a time period effective to render the silica dielectric film hydrophobic;

and

(b) removing unreacted surface modification composition, reaction products and mixtures thereof,

wherein the surface modification composition comprises at least one surface modification agent suitable for removing silanol moieties from the damaged silica dielectric film.

2. The method of claim 1 wherein the etchant-damaged silica dielectric film is subjected to wet cleaning prior to step (a).

3. The method of claim 1 wherein the surface modification composition comprises at least one compound having a formula selected from the group consisting of:

R₃SiNHSiR₃, RxSiCly, RxSi(OH)y R₃SiOSiR₃, RxSi(OR)y, MpSi(OH)[4−

p], RxSi(OCOCH₃)y and combinations thereof,

wherein x is an integer ranging from 1 to 3,

y is an integer ranging from 1 to 3 such that y=4−

x,

p is an integer ranging from 2 to 3;

each R is an independently selected from hydrogen and a hydrophobic organic moiety;

each M is an independently selected hydrophobic organic moiety; and

R and M can be the same or different.

4. The method of claim 1 wherein the surface modification composition comprises at least a compound selected from the group consisting of, acetoxytrimethylsilane, acetoxysilane, diacetoxydimethylsilane, methyltriacetoxysilane, phenyltriacetoxysilane, diphenyldiacetoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, trimethylethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorsilane, methylsilane, dimethylsilane, trimethylsilane, hexamethyldisilazane, 2-trimethylsiloxypent-2-ene-4-onc, n-(trimethylsilyl)acetamide, 2-(trimethylsilyl) acetic acid, n-(trimethylsilyl)imidazole, trimethylsilylpropiolate, trimethylsilyl(trimethylsiloxy)-acetate, nonamethyltrisilazane, hexamethyldisiloxane, trimethylsilanol, triethylsilanol, triphenylsilanol, t-butyldimethylsilanol, diphenylsilanediol, trimethoxysilane, triethoxysilane, trichlorosilane, and combinations thereof.

5. The method of claim 4 wherein the surface modification composition comprises methyltriacetoxysilane.

6. The method of claim 1 wherein the silica dielectric film is either nanoporous or non-porous.

7. The method of claim 1 wherein the silica dielectric film is a methylhydridosiloxane film.

8. The method of claim 1 wherein the surface modification composition comprises a solvent selected from the group consisting of ketones, ethers, esters, hydrocarbons, and combinations thereof.

9. The method of claim 1 wherein the etchant is a plasma comprising atoms, ions and/or radicals selected from the group consisting of oxygen, fluorine, hydrogen, nitrogen and combinations thereof.

10. The method of claim 1 wherein the etchant is a wet etchant that comprises at least one agent selected from the group consisting of an amide, an alcohol, an alcoholamine, an amine, a triamine, an acid, a base and combinations thereof.

11. The method of claim 10 wherein the amide is selected from the group consisting of N-methylpyrrolidinone, dimethylformamide, dimethylacetamide and combinations thereof.

12. The method of claim 10 wherein the alcohol is selected from the group consisting of ethanol 2-propanol and combinations thereof.

13. The method of claim 10 wherein the etchant comprises at least one agent selected from the group consisting of ethanolamine, ethylenediamine, triethylamine, N,N-diethylethylenediamine, diethylenetriamine, amine, ethylenediaminetetracetic acid;

organic, acetic acid, formic acid, tetramethylammonium acetate, sulfuric acid, phosphoric acid, hydrofluoric acid;

ammonium fluoride, ammonium hydroxide, tetramethyl ammonium hydroxide, hydroxl amine and combinations thereof, provided that the combinations are of agents that do not neutralize one another.

14. The method of claim 1 wherein the surface modification composition is contacted with the damaged silica dielectric film in a state selected from the group consisting of liquid, vapor or gas, and plasma.

15. The method of claim 14 wherein a plasma derived from a silane compound is used as the surface modification composition.

16. The method of claim 14 wherein the surface modification composition is a plasma derived from a compound selected from the group consisting of a hydrocarbon, an aldehyde, an ester, an ether, and combinations thereof.