Chemical mechanical polishing method for cobalt with high cobalt removal rates and reduced cobalt corrosion

Patent metadata

Field	Value
Publication number	US-10947413-B2
Application number	US-201916369085-A
Country	US
Kind code	B2
Filing date	Mar 29, 2019
Priority date	Mar 29, 2019
Publication date	Mar 16, 2021
Grant date	Mar 16, 2021

Abstract

A process for chemical mechanical polishing cobalt to planarize the surface and remove at least some of the cobalt from a substrate. The process includes providing a polishing composition, containing, as initial components: water; an oxidizing agent; colloidal silica abrasive particles; aspartic acid or salts thereof; a phosphonic acid having an alkyl group of greater than ten carbon atoms, wherein the phosphonic acid having the alky group of greater than ten carbon atoms is included in amounts sufficient to enable high cobalt removal rates of ≥2000 Å/min and substantial cobalt corrosion inhibition; and providing a chemical mechanical polishing pad, having a polishing surface; creating dynamic contact at an interface between the polishing pad and the substrate; and dispensing the polishing composition onto the polishing surface at or near the interface between the polishing pad and the substrate; wherein some of the cobalt is polished away and cobalt corrosion is substantially inhibited.

First claim

What is claimed is:

1. A method of chemical mechanical polishing cobalt, comprising:
providing a substrate comprising cobalt;
providing a chemical mechanical polishing composition, consisting of, as initial components:
water;
an oxidizing agent;
0.3 wt % to 1 wt % aspartic acid or salts thereof;
colloidal silica abrasive particles; and
a phosphonic acid or salt thereof having a formula:

wherein R is a linear alkyl group of twelve to eighteen carbon atoms, and wherein the phosphonic acid or salt thereof is in amounts of 0.0001 wt % to 0.001 wt %; and
optionally a biocide;
optionally, a pH adjusting agent selected from the group consisting of potassium hydroxide and nitric acid;
optionally, a surfactant; and
wherein a pH of the chemical mechanical polishing composition is from 7-11;
providing a chemical mechanical polishing pad, having a polishing surface;
creating dynamic contact at an interface between the chemical mechanical polishing pad and the substrate; and
dispensing the chemical mechanical polishing composition onto the polishing surface of the chemical mechanical polishing pad at or near the interface between the chemical mechanical polishing pad and the substrate to remove at least some of the cobalt.

2. The method of claim 1 , wherein the chemical mechanical polishing composition provided has a cobalt removal rate of ≥2000 Å/min with a platen speed of 93 revolutions per minute, a carrier speed of 87 revolutions per minute, a chemical mechanical polishing composition flow rate of 200 mL/min, a nominal down force of 13.8 kPa on a 200 mm polishing machine; and, wherein the chemical mechanical polishing pad comprises a polyurethane polishing layer containing polymeric hollow core microparticles and a polyurethane impregnated non-woven subpad.

3. The method of claim 1 , wherein the phosphonic acid of the chemical mechanical polishing composition provided is selected from the group consisting of dodecylphosphonic acid, tetradecylphosphonic acid and salts thereof.

Assignees

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

Inventors

• Theivanayagam Murali Ganth

Classifications

• H10P52/403

  of conductive or resistive materials · CPC title

• H10W20/062

  by smoothing of conductive parts, e.g. by planarisation · CPC title

• C09K3/1463

  Aqueous liquid suspensions · CPC title

• C09G1/02 Primary

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

• C09K3/1409

  Abrasive particles per se (preparation of diamond C01B32/25) · CPC title