Gallium and chromium ions for oxide rate enhancement
View Patent ↗The invention provides a chemical-mechanical polishing composition comprising silica, a compound in an amount sufficient to provide about 0.2 mM to about 10 mM of a metal cation selected from the group consisting of gallium (III), chromium (II), and chromium (III), and water, wherein the polishing composition has a pH of about 1 to about 6. The invention further provides a method of chemically-mechanically polishing a substrate with the aforementioned polishing composition.
1. A chemical-mechanical polishing composition consisting of:
(a) condensation-polymerized silica,
(b) a compound in an amount sufficient to provide about 0.2 mM to about 10 mM of a metal cation selected from the group consisting of gallium (III), chromium (II), and chromium (III),
(c) a pH adjusting agent selected from the group consisting of nitric acid, sulfuric acid, phosphoric acid, ammonium hydroxide, or potassium hydroxide,
(d) optionally, a biocide, and
(e) water,
wherein the polishing composition has a pH of about 1 about 6.
2. The polishing composition of claim 1 , wherein the silica is present in the amount of about 0.1 wt. % to about 10 wt. %.
3. The polishing composition of claim 1 , where the silica has a mean particle size of about 10 nm to about 80 nm.
4. The polishing composition of claim 1 , wherein the compound comprises a salt comprising an anion selected from the group consisting of acetate, chloride, nitrate, and sulfate.
5. The polishing composition of claim 1 , wherein the compound is gallium nitrate.
6. The polishing composition of claim 5 , wherein the gallium nitrate is present in a concentration of about 1 mM to about 8 mM.
7. The polishing composition of claim 1 , wherein the pH is about 2 to about 5.
8. The polishing composition of claim 7 , wherein the pH is about 2 to about 4.
9. A method of chemically-mechanically polishing a substrate, which method comprises:
(i) providing a substrate,
(ii) contacting the substrate with a polishing pad and a chemical-mechanical polishing composition consisting of:
(a) condensation-polymerized silica,
(b) a compound in an amount sufficient to provide about 0.2 mM to about 10 mM of a metal cation selected from the group consisting of gallium (III), chromium (II), and chromium (III),
(c) a pH adjusting agent selected from the group consisting of nitric acid, sulfuric acid, phosphoric acid, ammonium hydroxide, or potassium hydroxide,
(d) optionally, a biocide, and
(e) water,
wherein the polishing composition has a pH of about 1 to about 6,
(iii) moving the polishing pad relative to the substrate with the chemical-mechanical polishing composition therebetween, and
(iv) abrading at least a portion of the substrate to polish the substrate.
10. The method of claim 9 , wherein the silica is present in the amount of about 0.1 wt. % to about 10 wt. %.
11. The method of claim 9 , where the silica has a mean particle size of about 10 nm to about 80 nm.
12. The method of claim 9 , wherein the compound comprises a salt comprising an anion selected from the group consisting of acetate, chloride, nitrate, and sulfate.
13. The method of claim 9 , wherein the compound is gallium nitrate.
14. The method of claim 13 , wherein the gallium nitrate is present in a concentration of about 1 mM to about 8 mM.
15. The method of claim 9 , wherein the pH is about 2 to about 5.
16. The method of claim 15 , wherein the pH is about 2 to about 4.
17. The method of claim 9 , wherein the substrate comprises a dielectric layer.
18. The method of claim 17 , wherein the dielectric layer is selected from the group consisting of silicon dioxide, carbon-doped silicon dioxide, and organically modified silicon glass.
19. The method of claim 18 , wherein the substrate further comprises at least one metal layer.
20. The method of claim 19 , wherein the at least one metal layer is selected from the group consisting of aluminum, copper, tungsten, and combinations thereof.
21. The method of claim 20 , wherein the substrate further comprises at least one barrier layer.
22. The method of claim 21 , wherein the at least one barrier layer is selected from the group consisting of tantalum, titanium, nitrides thereof, and combinations thereof.