better cmp cleaning solutions surfactanized metal inhibitors, oxygen scavengers and a new particle...
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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
March 19 2014 CMPUG 2014 San Jose
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
March 19 2014 CMPUG 2014 San Jose
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)
March 19 2014 CMPUG 2014 San Jose
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
March 19 2014 CMPUG 2014 San Jose
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
March 19 2014 CMPUG 2014 San Jose
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
March 19 2014 CMPUG 2014 San Jose
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
March 19 2014 CMPUG 2014 San Jose
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
March 19 2014 CMPUG 2014 San Jose
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
March 19 2014 CMPUG 2014 San Jose
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
March 19 2014 CMPUG 2014 San Jose
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%
March 19 2014 CMPUG 2014 San Jose
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
March 19 2014 CMPUG 2014 San Jose
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
March 19 2014 CMPUG 2014 San Jose
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
March 19 2014 CMPUG 2014 San Jose
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
March 19 2014 CMPUG 2014 San Jose
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
March 19 2014 CMPUG 2014 San Jose
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