Claims
- 1. An aqueous composition for chemical-mechanical polishing of a semiconductor substrate with a noble metal layer, a barrier layer, and a dielectric layer, said composition comprising:
abrasive particles present at a concentration from about 0.5% to about 55% by weight of said polishing composition; an organic compound up to about 10% by weight of the polishing composition; and a ligand-containing compound at about 0.1% to about 50% by weight of the polishing composition, with said ligand having a stability constant with said noble metal in a range of about 5 to about 100; said polishing composition providing a high selectivity between a metal layer and a dielectric layer or a metal layer and a barrier layer of a semiconductor device.
- 2. A composition according to claim 1 wherein said selectivity is in a range of about 1:1 to about 100:1.
- 3. A composition according to claim 2 wherein the ligand-containing compound is an inorganic sulfur-containing compound or an organic sulfur-containing compound.
- 4. A composition according to claim 3 wherein the sulfur-containing organic compound is selected from the group consisting of aromatic sulfide, aromatic sulfoxide, amino alkyl thiols, alkyl mercaptans, mercaptocarboxylate esters, thioglycolic acid, mercaptoalanines, mercaptoaromatic acids, mercaptoaromatic thiazoles, mercaptoaromatic thiazyl disulfides, mercaptoalkanols, mercaptoalkyl amine hydrochlorides, mercaptoalkyl aromatic sulfonamides, mercaptopropionic acid and mercapto succinic acid.
- 5. A composition according to claim 3 wherein the sulfur-containing inorganic compound is a metal salt of an acid selected from the group consisting of thiosulfuric acid, disulfurous acid, polythionic acid, peroxodisulfuric acid and combinations thereof.
- 6. A composition according to claim 5 wherein said abrasive is selected from the group consisting of alumina, ceria, silica, diamond, germania, zirconia, silicon carbide, boron nitride, boron carbide or combinations thereof.
- 7. A composition according to claim 6 wherein the organic compound has a moiety selected from the group consisting of hydroxy, carboxy, thiol, mercapto, and amino.
- 8. A composition according to claim 7 wherein said organic compound is an organic acid selected from the group consisting of dicarboxylic acids, tricarboxylic acids and hydroxy acids.
- 9. A composition according to claim 8 wherein said abrasive is alpha-alumina.
- 10. A composition according to claim 9 wherein the tricarboxylic acid is citric acid.
- 11. A composition according to claim 10 wherein the pH of the aqueous composition is in a range of about 1.5 to about 5.
- 12. A composition according to claim 11 wherein a stable pH value is attained by the addition of aluminum (III) ions at a molar concentration up to about 10 M.
- 13. A composition according to claim 8 wherein the hydroxy acid is malic acid.
- 14. A composition according to claim 8 wherein the hydroxy acid is lactic acid.
- 15. A method of polishing a surface of a semiconductor substrate having a noble metal circuit comprising the steps of:
i. positioning said substrate in a polishing machine such that the substrate is fixedly attached to a carrier in said polishing machine; ii. providing a polishing pad with a polishing layer having a polishing surface, fixedly attached to a platen in said polishing machine; iii. contacting said substrate fixedly attached to the carrier and the polishing pad fixedly attached to the platen while maintaining a relative motion between the pad and the substrate under a fixed pressure or downforce; and iv. dispensing an aqueous polishing composition onto the polishing pad at the interface of the substrate and the polishing surface of the polishing pad so that the moving pressurized contact of the substrate against the polishing pad results in a substantially planarized surface of the substrate; wherein the polishing composition is the polishing composition of claim 1.
- 16. A method according to claim 15 performed with the polishing composition is of claim 9.
- 17. A method according to claim 15 performed with the polishing composition is of claim 10.
- 18. A method according to claim 15 performed with the polishing composition is of claim 11.
- 19. A method according to claim 15 performed with the polishing composition is of claim 12.
Parent Case Info
[0001] This utility application claims the benefit of U.S. Provisional Patent Application No. 60/170,612 filed on Dec. 14, 1999 and U.S. Provisional Patent Application No. 60/171,553 filed on Dec. 22, 1999.
Provisional Applications (2)
|
Number |
Date |
Country |
|
60171553 |
Dec 1999 |
US |
|
60170612 |
Dec 1999 |
US |