Aqueous silica slurry compositions for use in shallow trench isolation and methods of using them

Patent metadata

Field	Value
Publication number	US-10221336-B2
Application number	US-201715680730-A
Country	US
Kind code	B2
Filing date	Aug 18, 2017
Priority date	Jun 16, 2017
Publication date	Mar 5, 2019
Grant date	Mar 5, 2019

Abstract

The present invention provides aqueous CMP polishing compositions comprising a from 0.5 to 30 wt. %, based on the total weight of the composition of a dispersion of a plurality of elongated, bent or nodular colloidal silica particles which contain a cationic nitrogen atom, and from 0.001 to 0.5 wt. %, preferably from 10 to 500 ppm, of a cationic copolymer of a diallyldimethylammonium salt, such as a diallyldimethylammonium halide, wherein the compositions have a pH of from 1 to 4.5. Preferably, the cationic copolymer of a diallyldimethylammonium salt comprises a copolymer of diallyldimethylammonium chloride (DADMAC) and sulfur dioxide. The slurry compositions demonstrate good oxide selectivity in the CMP polishing of pattern wafers having nitride and silicon patterns.

First claim

We claim:

1. An aqueous chemical mechanical planarization polishing composition consisting of water, a dispersion of a plurality of elongated, bent or nodular colloidal silica particles which contain a cationic nitrogen atom, an acid selected from the group consisting of sulfuric acid and nitric acid, and from 10 to 500 ppm of a cationic copolymer of a diallyldimethylammonium salt consisting of a copolymer of a diallyldimethylammonium halide salt and sulfur dioxide, wherein the composition has a pH of from 1 to 4.5 and, further wherein, the amount of the dispersion of the elongated, bent or nodular colloidal silica particles, ranges from 0.5 to 30 wt. %, all weights based on the total weight of the composition.

2. The aqueous chemical mechanical planarization polishing composition as claimed in claim 1 , wherein the dispersion of elongated, bent or nodular colloidal silica particles have for the average particle an aspect ratio of longest dimension to the diameter which is perpendicular to the longest dimension from 1.8:1 to 3:1.

3. The aqueous chemical mechanical planarization polishing composition as claimed in claim 1 , wherein the amount of the dispersion of elongated, bent or nodular colloidal silica particles ranges from 80 to 99.9 wt. %, based on the total solids weight of the colloidal silica particles in the composition.

4. The aqueous chemical mechanical planarization polishing composition as claimed in claim 1 , wherein the cationic copolymer of a diallyldimethylammonium salt consists of a copolymer of diallyldimethylammonium chloride and sulfur dioxide.

5. The aqueous chemical mechanical planarization polishing composition as claimed in claim 4 , wherein the cationic copolymer of a diallyldimethylammonium salt consisting of a copolymer of diallyldimethylammonium halide and sulfur dioxide has a weight average molecular weight of from 1,000 to 15,000.

6. The aqueous chemical mechanical planarization polishing composition as claimed in claim 4 , wherein the cationic copolymer of a diallyldimethylammonium salt consists of a copolymer of diallyldimethylammonium chloride and sulfur dioxide in amounts of 10-20 ppm.

7. The aqueous chemical mechanical planarization polishing composition as claimed in claim 1 , wherein the cationic copolymer of a diallyldimethylammonium salt consists of a copolymer of 45 to 55 mole % of the diallyldimethylammonium halide salt and from 45 to 55 mole % of the sulfur dioxide.

8. The aqueous chemical mechanical planarization polishing composition as claimed in claim 1 , wherein the composition has a pH of from 2.5 to 4.3.

9. A method of using the aqueous chemical mechanical planarization polishing composition as claimed in claim 1 , comprising: polishing a substrate with a chemical mechanical polishing pad and the aqueous chemical mechanical polishing composition.

10. The method as claimed in claim 9 , wherein the substrate comprises both silicon dioxide and silicon nitrides, and the polishing results in an oxide:nitride removal rate ratio of from 3:1 to 25:1.

Assignees

• Rohm & Haas Elect Materials Cmp Holdings Inc
• Rohm And Hass Electronic Mat Cmp Holdings Inc

Inventors

• Kozhukh Julia
• Mosley David
• Penta Naresh Kumar
• Van Hanehem Matthew
• Reddy Kancharla-Arun K

Classifications

• H10P95/062

  involving a dielectric removal step · CPC title

• H10P52/403

  of conductive or resistive materials · CPC title

• H10P52/402

  of semiconductor materials · CPC title

• H10W10/17

  formed using trench refilling with dielectric materials, e.g. shallow trench isolations · CPC title

• H10P95/064

  the removal being chemical etching · CPC title