Polishing composition and use thereof

• US 20050076580A1
• Filed: 10/10/2003
• Published: 04/14/2005
• Est. Priority Date: 10/10/2003
• Status: Abandoned Application

• Current Assignee: Versum Materials US Inc.
• Original Assignee: Air Products and Chemicals Incorporated (Linde Plc)
• Inventors: Banerjee, Gautam, Hymes, Stephen W., Tamboli, Dynanesh
• Application Number:
  US10/683,553
• Publication Number:
  US 20050076580A1
• Time in Patent Office: Days
• US Class Current: 51/307
• CPC Class Codes: C09G 1/02 containing abrasives or grinding agents abrasives as such C09K3/14; polishing of semi-conductors H01L
• CPC Class Codes: C09K 3/1463 Aqueous liquid suspensions
• CPC Class Codes: C23F 3/00 Brightening metals by chemical means
• CPC Class Codes: H01L 21/3212 by chemical mechanical polishing [CMP]

Abstract

An acidic aqueous slurry composition comprising silica abrasive particles, an oxidizer, a quaternary ammonium hydroxide; and acid having a maximum pKa of about 2.5; and water is provided along with its use for polishing.

Claims

1. An aqueous slurry composition which comprises:

A. about 0.01% by weight to about 50% by weight of abrasive particles;

B. about 0.01% to about 50% by weight of an oxidizer;

C. at least about 500 ppm of a quaternary ammonium hydroxide;

D. an acid having a pKa of about 2.5 or lower in an sufficient amount to provide an acidic pH; and

E. water.

2. The composition of claim 1 wherein the amount of the abrasive particles is about 1% to about 20% by weight.

3. The composition of claim 1 wherein the amount of the abrasive particles is about 5% to about 15% by weight.

4. The composition of claim 1 wherein the abrasive particles comprises silica particles.

5. The composition of claim 1 wherein the oxidizer comprises hydrogen peroxide.

6. The composition of claim 1 wherein the amount of oxidizer is about 0.05 at % to about 5 wt %.

7. The composition of claim 1 wherein the amount of oxidizer is about 0.1 wt, % to about 1 wt. %.

8. The composition of claim 1 wherein the quaternary ammonium hydroxide is represented by the formula:

[NR₄R₅R₆R₇]⁻

OH

wherein each of R₄, R₅R₆ and R₇ individually is an alkyl group of 1 to 20 carbon atoms.

9. The composition of claim 8 wherein the alkyl group contains 1 to 4 carbon atoms.

10. The composition of claim 1 wherein the quaternary ammonium hydroxide comprises tetramethyl ammonium hydroxide or tetrabutyl ammonium hydroxide.

11. The composition of claim 1 wherein the amount of quaternary ammonium hydroxide is about 1000 ppm or higher.

12. The composition of claim 1 wherein the amount of quaternary ammonium hydroxide is about 2500 ppm or higher.

13. The composition of claim 1 wherein the acid comprises phosphoric acid.

14. The composition of claim 1 wherein the pH is at least about 1.5.

15. The composition of claim 1 wherein the pH is about 1.5 to about 5.

16. The composition of claim 1 wherein the pH is at least about 2.

17. The composition of claim 1 which further comprises a corrosion inhibitor.

18. The composition of claim 16 wherein the corrosion inhibitor comprises benzotriazole.

19. The composition of claim 1 which further comprises a surface active agent.

21. A process for fabricating semiconductor integrated circuit structure comprising:

forming circuits on the surface of a semiconductor wafer by photolithographic process;

planarizing the surface by chemical mechanical polishing with the composition of claim 1.

22. The process of claim 21 wherein the integrated circuit structure comprise a semiconductor substrate;

a ferromagnetic metal layer;

a metal selected from the group consisting of group 3d and 5d of the periodic table;

a layer of copper or aluminum;

a barrier layer; and

a dielectric layer.

20. A method for polishing a metal which comprises providing on the metal an aqueous slurry composition comprising:

A. about 0.1% by weight to about 50% by weight of abrasive particles;

B. about 0.1% to about 50% by weight of an oxidizer;

C. at least about 500 ppm of a quaternary ammonium hydroxide;

D. an acid being a pKa of about 2.5 or lower in amount to provide an acidic pH;

and E. water;

and contacting the metal with a polishing pad.