US 6,720,264 B2Granted

Prevention of precipitation defects on copper interconnects during CMP by use of solutions containing organic compounds with silica adsorption and copper corrosion inhibiting properties

AssigneeAdvanced Micro Devices, Inc.

InventorsKashmir S. Sahota, Diana M. Schonauer, Johannes F. Groschopf, Gerd F. C. Marxsen, Steven C. Avanzino

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Abstract

A Ta barrier slurry for Chemical-Mechanical Polishing (CMP) during copper metallization contains an organic additive which suppresses formation of precipitates and copper staining. The organic additive is chosen from a class of compounds which form multiple strong adsorbant bonds to the surface of silica or copper, which provide a high degree of surface coverage onto the reactive species, thereby occupying potential reaction sites, and which are sized to sterically hinder the collisions between two reactant molecules which result in new bond formation. The organic additive-containing slurry cain be utilized throughout the entire polish time. Alternatively, a slurry not containing the organic additive can be utilized for a first portion of the polish, and a slurry containing the organic additive or a polishing solution containing the organic additive can be utilized for a second portion of the polish.

Claims15

Dependent claims

A Chemical-Mechanical Polishing (CMP) method for polishing Ta barrier layers in integrated circuit metallization structures including copper and silica, said method including flowing polishing slurry containing silica abrasive, DI water, and a copper passivation agent, onto a platen, inducing relative motion between said wafer and said platen and maintaining a force between said platen and said wafer, and removing said wafer from against said platen, said polishing occurring for a total polishing period of time, comprising,

incorporating into said polishing slurry for a final portion of said total polishing period of time less than or equal to 10% of said total polishing period of time, an organic additive selected from the group consisting of:
polyvinyl alcohol (PVA), PVA-poly(vinyl acetate) co-polymer, PVA-polyethylene co-polymer, sorbitol, glycerol, polyacrylamide (PAA), ethylene glycol, di(ethylene glycol), poly(ethylene glycol) (PEG), glycerol ethoxylate (GEO), dimethylsiloxane-ethylene oxide co-polymer (DMSiO-EO), polyethylene oxide surfactants, octylphenol polyethylene oxide, nonylphenol polyethylene oxide, polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, perfluorinated analogs of polyethylene oxide surfactants, glycerol propoxylate (GPO), organic amines, N,N-diethylcyclohexylamine (DCA), and polyethyleneimine (PEI);
said organic additive not being included in said polishing slurry prior to said final portion of said total polishing period of time.

In a Chemical-Mechanical Polishing (CMP) method for polishing Ta barrier layers in integrated circuit metallization structures including copper and silica, said method including flowing polishing slurry containing silica abrasive, DI water, and a copper passivation agent onto a platen, inducing relative motion between said wafer and said platen while maintaining a force between said platen and said wafer, and removing said wafer from against said platen, said polishing occurring for a first polishing period of time, the improvement comprising:

decreasing said flow of said polishing slurry prior to said step of removing said wafer from against said platen;
and
following said step of decreasing said flow of said polishing slurry and prior to said step of removing said wafer from against said platen, flowing a polishing additive solution onto said platen for a second period of time while inducing relative motion between said wafer and said platen and maintaining a force between said platen and said wafer;
said polishing additive solution comprising;
DI water;
a copper passivation agent selected from the group consisting of,
1,2,4-triazole, benzotriazole (BTA), imidazole, 5-methyl benzimidazole, polyaniline, indazole, and purine;
and
an organic additive selected from the group consisting of,
polyvinyl alcohol (PVA), PVA-poly(vinyl acetate) co-polymer, PVA-polyethylene co-polymer, sorbitol, glycerol, polyacrylamide (PAA), ethylene glycol, di(ethylene glycol), poly(ethylene glycol) (PEG), glycerol ethoxylate (GEO), dimethylsiloxane-ethylene oxide co-polymer (DMSiO-EO), polyethylene oxide surfactants, octylphenol polyethylene oxide, nonylphenol polyethylene oxide, polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, perfluorinated analogs of polyethylene oxide surfactants, glycerol propoxylate (GPO), organic amines, N,N-diethylcyclohexylamine (DCA), and polyethyleneimine (PEI);
said polishing slurry not including said organic additive prior to said step of flowing said polishing additive solution.

8 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/749,191Filed 26 Dec 2000 · continuation in part
Priority: 4 Nov 1999
Published: US 2004/0014319 A122 Jan 2004
Granted: 13 Apr 2004
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

C09K 3/1463
Abrasive powders, suspensions and pastes for polishing: aqueous liquid suspensions
C09G 1/02
Polishing compositions: containing abrasives or grinding agents
H10P 52/403
Chemomechanical polishing [CMP]: of conductive or resistive materials
C09K
Materials for miscellaneous applications, not provided for elsewhere

Family

Application09/434,146Parent of this continuation-in-part · filed 4 Nov 1999
US 2004/0014319 A1Pre-grant publication · published 22 Jan 2004
US 6,503,418 B2Parent of this continuation-in-part
US 2002/0005504 A1Published application
US 6,720,264 B2This patent

From the US filing history. Foreign family members aren’t listed.