Method for cleaning post-etch noble metal residues

1. A method of manufacturing a semiconductor device, comprising:

forming conductive and ferroelectric material layers on a semiconductor substrate;

patterning said material layers to form electrodes and a ferroelectric layer of a ferroelectric capacitor, wherein a conductive noble metal-containing polymer is generated on sidewalls of said ferroelectric capacitor; and

converting said conductive noble metal-containing polymer into a non-conducting metal oxide, including:

forming a water-soluble metal salt from said conductive noble metal-containing polymer;

reacting said water-soluble metal salt with an aqueous acidic solution to form a metal hydroxide; and

oxidizing said metal hydroxide to form said non-conducting metal oxide.

2. The method of claim 1 , wherein said reacting comprises exposing said water-soluble metal salt to said aqueous acidic solution at a temperature of between about 60 and 100° C.

3. The method of claim 1 , wherein said reacting includes exposing said water-soluble metal salt to said acid aqueous acidic solution having about 50 wt% phosphoric acid.

4. The method of claim 1 , wherein said reacting includes exposing said water-soluble metal salt to said acid aqueous acidic solution having hydrochloric acid and hydrogen peroxide.

5. The method of claim 1 , wherein said reacting includes exposing said water-soluble metal salt to said acid aqueous acidic solution having a carboxylic acid.

6. The method of claim 1 , wherein said reacting includes exchanging one or more halides of said water-soluble metal salt with one or more anionic ligands of said aqueous acidic solution.

7. The method of claim 1 , wherein said oxidizing includes exposing said metal hydroxide to a plasma comprising oxygen as a feed gas.

8. The method of claim 1 , wherein said oxidizing includes exposing said metal hydroxide to a RF plasma with at least about 66% oxygen as a feed gas, and a power of least about 700 Watts.

9. The method of claim 1 , wherein said patterning said material layers includes covering portion of said material layers with a hard mask and removing uncovered portions of said material layers using a reactive ion etching (RIE) process that includes halogen, oxygen and fluorocarbon feed gases.

10. The method of claim 1 , wherein said water-soluble metal salt comprises a salt selected from the group consisting of: a metal hydroxide salt, a metal hydride salt.

11. The method of claim 1 , wherein said aqueous acidic solution is an aqueous solution comprising at least one acid selected from the group consisting of: phosphoric acid; sulfuric acid; hydrochloric acid; EDTA, acetylacetonate, acetic acid, oxalic acid or other carboxylic acid.

12. The method of claim 1 , wherein forming said water-soluble metal salt includes hydrolyzing said conductive noble metal-containing polymer.

13. The method of claim 12 , wherein said hydrolyzing includes exposing said conductive noble metal-containing polymer to a plasma generated using H 2 O as a feed gas.

14. The method of claim 1 , wherein forming said water-soluble metal salt includes halogenating said conductive noble metal-containing polymer.

15. The method of claim 14 , wherein said halogenating includes exposing said conductive noble metal-containing polymer to a plasma generated using a halogen as a feed gas.

16. A method of manufacturing an integrated circuit, comprising:

forming one or more transistors on a semiconductor substrate;

depositing a pre-metal dielectric layer over said transistors;

fabricating a ferroelectric capacitor on said semiconductor substrate, wherein said ferroelectric capacitor is electrically coupled to at least one of said transistors, including:

forming conductive and ferroelectric material layers on said pre-metal dielectric layer;

patterning said material layers to form electrodes and a ferroelectric layer of said ferroelectric capacitor, wherein a conductive noble metal-containing polymer is generated on sidewalls of said ferroelectric capacitor; and

converting said conductive noble metal-containing polymer into an non-conducting metal oxide, including:

forming a water-soluble metal salt from said conductive noble metal-containing polymer;

reacting said water-soluble metal salt with an aqueous acidic solution to form a metal hydroxide; and p 3 oxidizing said metal hydroxide to form said non-conducting metal oxide.

17. The method of claim 16 , wherein forming said water-soluble metal salt includes hydrolyzing said conductive noble metal-containing polymer by exposing said conductive noble metal-containing polymer to a RF plasma generated using an O 2 :N 2 :H 2 O sccm ratio of about 20:2:3 to about 40:2:5 as a feed gas, a plasma power of about 1000 to 2000 Watts, and a chuck temperature of about 50 to 350° C.

18. The method of claim 16 , wherein said reacting includes exposing said water-soluble metal salt to said acid aqueous acidic solution comprising about 50 wt% phosphoric acid at about 65° C.

19. The method of claim 16 , wherein said oxidizing includes exposing said metal hydroxide to a RF plasma with about 70% oxygen as a feed gas and a power of about 700 Watts.

20. The method of claim 16 , wherein said one or more transistors and said ferroelectric capacitor are interconnected to form a memory cell.

21. The method of claim 16 , wherein:

forming said water-soluble metal salt includes hydrolyzing said conductive noble metal-containing polymer by exposing said conductive noble metal-containing polymer to a RF plasma generated using an O 2 :N 2 :H 2 O sccm ratio of about 3500:200:300 to 3500:200:500 as a feed gas, a plasma power of about 1400 Watts, and a chuck temperature of about 300° C. for about 60 seconds;

reacting said water-soluble metal salt comprises exposure to said acid aqueous acidic solution comprising about 50 wt% phosphoric acid at about 65° C.; and

oxidizing said metal hydroxide includes a RF plasma with about 70% oxygen as a feed gas and a power of about 700 Watts.

22. A method of manufacturing a semiconductor device, comprising:

forming one or more noble metal layers on a semiconductor substrate;

patterning said one or more noble metal layers by etching;

removing conductive film left by noble metal layer reaction in said etching, by oxidizing said film and complexing said oxidizing film with a labile ligand.

23. The method of claim 22 , wherein said labile ligand is subsequently replaced by a stronger ligand.

24. The method of claim 23 , wherein:

forming said one of more noble metal layers comprises forming conductive and ferroelectric material layers on said semiconductor substrate;

patterning said one or more noble metal layers comprises patterning said material layers to form electrodes and a ferroelectric layer of a ferroelectric capacitor; and

removing said conductive film comprises removing a conductive noble metal-containing polymer generated on sidewalls of said ferroelectric capacitor by converting said conductive noble metal-containing polymer film into a non-conducting metal oxide, including:

forming a water-soluble metal salt from said conductive noble metal-containing polymer;

reacting said water-soluble metal salt with an aqueous acidic solution to form a metal hydroxide; and

oxidizing said metal hydroxide to form said non-conducting metal oxide.

25. The method of claim 24 , wherein said noble metal is Ir; said etching comprises a plasma etch which converts Ir to an insoluble plasma etch byproduct IRF3; said insoluble plasma etch byproduct is converted into a soluble hydrate IrCl 2 (OH)-3H 2 O using plasma assisted passivation; such hydrate is dissolved to from a non-conducting oxide Ir(OH) 3 ; and surfaces of the sidewalls are repassivated by converting the non-conducting oxide into a high O 2 content IrOx through plasma assisted oxidation.

26. The method of claim 23 , wherein said etching is a dry etch in the presence of oxygen.

27. The method of claim 26 , wherein an oxychloride of said noble metal is converted to a chloride salt by treatment with HCL and an oxidant mixture.

28. The method of claim 27 , wherein said noble metal is Pt, Ru or Ir.