Better CMP Cleaning Solutions Surfactanized Metal Inhibitors, Oxygen Scavengers and a New Particle Remover March 19 2014 CMPUG 2014 San Jose By Geoffrey

Better CMP Cleaning Solutions

Surfactanized Metal Inhibitors, Oxygen Scavengersand a New Particle Remover

March 19 2014 CMPUG 2014 San Jose

By

Geoffrey Yuxin Hu, PhD, Brizon Inc

Lily Yao, PhD, Western Digital Technologies Inc


Introduction

Challenge of CMP in IC and HD

Background

Classic Principle of CMP Process

New Concepts of Slurry Chemistry and Formulation Outlet

Fab Experimental Data and Results

Future Developments

Summary

Acknowledgment


Challenge

Poor uniformity of the slurry on the pad

Macro- and micro- scratching

Residual slurry particles, Al2O3, Colloid SiO2 etal

Trace metals and ions (Cu, Ni, Fe)

Recontamination

Poor re-rinsibility

Etching, Corrosion ( aggressive chemicals,high or low pH, and oxidation)


Background

Unbalanced of Hydrophilic/Hydrophobic of Surfactants

Poor Vehicle of Slurry Poor uniformity of slurry on the pad

Poor Surface modification on particles, such as SiO2

Aggregation of particles Wide distribution of particles Macro- and micro- scratching

Poor re-rinsibility

Residual slurry particles, Al2O3, Colloid SiO2


Background

Micro incompatible of Metal Inhibitors/Oxygen Scavengers

Un-uniform dispersion of inhibitors in the solution Corrosion of metal Recontamination

Aggressive chemicals at high or low pH Corrosion Macro- or micro- scratching Poor re-rinsibility


Classic Principle

Higher pH (>10) Better removal of particles, specially BTA Corrosion on metal? Ni, Fe and Cu?

Classic Non-ionic Surfactants (NIS) Removing particles Removing organic contaminations

Ionic Surfactants (IS) Aliphatic phosphorous surfactants Metal surface protection Residual mono-layer

Chelating/Complex Chemicals Cleaning/removing metal ions and oxides


New Concepts

Surfactanized Metal Inhibitors Hydrophilic metal inhibitor on one side Short aliphatic hydrophobic tail Maximized protection on metal, Ni, Fe and Cu

Surfactanized Oxygen Scavenger Long ethoxylated hydrophilic tail Hydrophobic oxygen scavenger Max scavenged oxygen in whole CMP process

Special Surfactants Ethoxylated hydrophilic tail Short hydrophobic chain with chelate agent

Not ethylenediamine series Much better vehicle for particles, Al2O3, SiO2, etc

Optimized and Balanced Hydrophobic/Hydrophilic Media


Components

Special Non-ionic Surfactants

Mixed Surfactanized Metal inhibitorsAnd Oxygen Scavenger agents

Additional Metal inhibitors And Oxygen Scavenger agents

Surfactanized Chelating agents

Particle removing agents


How it works

HydrophilicMetal inhibitor head

AliphaticHydrophobic tail

Anti-oxidantHydrophobic Head

EthoxylatedHydrophilic Tail

+Briteclean-0+ Briteclean-1

Briteclean-0+ : Briteclean-1 = 1:1In 50X aqueous dilution

Briteclean-0+ : Briteclean-1 = 1:1Bulk solution

Phase separation


Application in a fab

Briteclean-0+ and Briteclean-1 blended 1:1 at a total concentration of 1.0 – 2.0% in aqueous media

Slurry applied: in MH837/MH834/MH814 (Cabot)

Pad applied: IC1000 (white pad --- Rodel/(Rohm Haas) Sub IV (black pad --- Rodel (Rohm Haas))

Tool platforms Applied: 8" Mirra (Applied Materials); 8" Ebara (Ebara); 8" 6DS-SP(Strausbaugh)

Wafer: Cu, Ni/Fe/Co, Low key and Al2O3


Briteclean Products

Briteclean – 0+ Briteclean - 1 Briteclean-ACP

Pre/Post Cleaning Process YES YES YES

Slurry Additives YES YES YES

Storage/Buffer NO NO YES

Application Need to mix with BC-1 or BC-ACP

Need to mix with BC-0+ Alone

Concentration 1% - 5% 1% - 5% 1% - 4%


Briteclean Application

pH

100% BriteClean-1

100% BriteClean-0+

Diluted 50X in DI H2O

Recommended Usage: Briteclean-0+/Briteclean-1 = 1:1 Diluted to 1%-5% with DI H2O

0 10 20 30 40 50 60 70 80 90 100

8.5

8 7.857.5

7.27

6.86.5

6.3

5.5

5


AFM Cu Plated Wafer

Roughness and surface residues are reduced

BriteClean Mixture

Average Roughness(N=3x3): Rms=0.29nm

Competitor’s Cleaning Solution

Average Roughness(N=3x3): Rms=0.34nm

SEM Cu Plated Wafer

BriteClean Mixture

Competitor’s Cleaning Solution

SEM Cu Plated Wafer


Slurry onlySlurry +

Brizon products


BriteClean Cleaning Solution Alumina NiFe

Con-1 -70 -66Con-2 -22 -340

Competitor Cleaning Solution Alumina NiFe

Con-1 190 280Con-2 1571 370

Different Slurry Cleanability BriteClean vs Competitor Particle Count


Particle counts

Competitor Cleaning Solution

Initial (Pre-)

Post Cleaning

(Post-Pre)

Alumina

Tool-1 477 1445 968

Tool-2 891 3065 2174

NiFe

Tool-3 133 528 395

Tool-4 500 845 345

BriteClean Cleaning Solution

Initial (Pre-)

Post Cleaning

(Post-Pre)

Alumina

Tool-1 259 268 9

Tool-2 692 640 -52

NiFe

Tool-3 675 123 -552

Tool-4 207 78 -129


Briteclean Application repeatability


New Developments

Briteclean-0+ More effective and efficiency cleaning Now in production in WD

Briteclean-Cu Only for Cu plated wafer High pH value >10 Novel agent for particle removal


Summary

Briteclean mixture maximizes CMP efficiency Uniformity Particles, metals No recontamination

Much improved surface roughness New designed chemistry Surface protection

Much easier process Mixture system No need to change processes


Acknowledgement

NCCAVS

Western Digital

Brizon Inc www.brizon.net

Documents

Better CMP Cleaning Solutions Surfactanized Metal Inhibitors, Oxygen Scavengers and a New Particle Remover March 19 2014 CMPUG 2014 San Jose By Geoffrey