Cobalt polishing accelerators

Patent metadata

Field	Value
Publication number	US-9850403-B2
Application number	US-201715603634-A
Country	US
Kind code	B2
Filing date	May 24, 2017
Priority date	Oct 21, 2014
Publication date	Dec 26, 2017
Grant date	Dec 26, 2017

Abstract

The invention provides a chemical-mechanical polishing composition comprising (a) abrasive particles, (b) a cobalt accelerator selected from a compound having the formula: NR 1 R 2 R 3 wherein R 1 , R 2 , and R 3 are independently selected from hydrogen, carboxyalkyl, substituted carboxyalkyl, hydroxyalkyl, substituted hydroxyalkyl and aminocarbonylalkyl, wherein none or one of R 1 , R 2 , and R 3 are hydrogen; dicarboxyheterocycles; heterocyclylalkyl-α-amino acids; N-(amidoalkyl)amino acids; unsubstituted heterocycles; alkyl-substituted heterocycles; substituted-alkyl-substituted heterocycles; N-aminoalkyl-α-amino acids; and combinations thereof, (c) a cobalt corrosion inhibitor, (d) an oxidizing agent that oxidizes a metal, and (e) water, wherein the polishing composition has a pH of about 3 to about 8.5. The invention further provides a method of chemically-mechanically polishing a substrate with the inventive chemical-mechanical polishing composition. Typically, the substrate contains cobalt.

First claim

The invention claimed is:

1. A method of chemically mechanically polishing a substrate comprising:
contacting a substrate with a polishing pad and a chemical-mechanical polishing composition comprising:
(a) abrasive particles,
(b) a cobalt accelerator selected from a compound having the formula: NR 1 R 2 R 3 wherein R 1 , R 2 , and R 3 are independently selected from hydrogen, carboxyalkyl, substituted carboxyalkyl, hydroxyalkyl, substituted hydroxyalkyl and aminocarbonylalkyl, wherein none or one of R 1 , R 2 , and R 3 are hydrogen; dicarboxyheterocycles; heterocyclylalkyl-α-amino acids; N-(amidoalkyl)amino acids; unsubstituted heterocycles; alkyl-substituted heterocycles; substituted-alkyl-substituted heterocycles; N-aminoalkyl-α-amino acids,

(c) a cobalt corrosion inhibitor, wherein the cobalt corrosion inhibitor comprises an anionic head group and a C 8 -C 14 aliphatic tail group; and combinations thereof,
(d) an oxidizing agent that oxidizes cobalt, and
(e) water,

wherein the polishing composition has a pH of about 3 to about 8.5,
(ii) moving the polishing pad and the chemical mechanical polishing composition relative to the substrate, and
(iii) abrading at least a portion of the substrate to polish the substrate.

2. The method of claim 1 , wherein the polishing composition comprises about 0.1 wt. % to about 2 wt. % of abrasive particles.

3. The method of claim 1 , wherein the cobalt accelerator is selected from iminodiacetic acid, picolinic acid, dipicolinic acid, bicine, [(2-amino-2-oxoethyl)amino]acetic acid, lysine, imidazole, histidine, and 2-[bis(2-hydroxyethyl)amino]-2-(hydroxymethyl)-1,3-propanediol.

4. The method of claim 1 , wherein the cobalt accelerator is present in the polishing composition in a concentration of about 5 mM to about 100 mM.

5. The method of claim 1 , wherein the cobalt corrosion inhibitor has the formula: RCON(CH 3 )COOH wherein R is a C 8 -C 13 aliphatic group.

6. The method of claim 1 , wherein the polishing composition comprises about 10 ppm to about 1000 ppm of the cobalt corrosion inhibitor.

7. The method of claim 1 , wherein the oxidizing agent is hydrogen peroxide.

8. The method of claim 1 , wherein the polishing composition has a pH of about 7 to about 8.

9. The method of claim 1 , wherein the substrate comprises cobalt, and least a portion of the cobalt is abraded to polish the substrate.

10. The method of claim 9 , wherein the substrate comprises a semiconductor device.

Assignees

• Cabot Microelectronics Corp

Inventors

• Kraft Steven
• Wolff Andrew
• Carter Phillip W
• Hayes Kristin
• Petro Benjamin

Classifications

• H10P52/403

  of conductive or resistive materials · CPC title

• C23F3/04

  Heavy metals · CPC title

• C09G1/02 Primary

  containing abrasives or grinding agents {(abrasives as such C09K3/14; polishing of semi-conductors H10P52/40)} · CPC title

• B24B37/044 Primary

  characterised by the composition of the lapping agent · CPC title

• H01L21/3212

  Electricity · mapped topic