Better CMP Cleaning Solutions Surfactanized Metal Inhibitors, Oxygen Scavengers and a New Particle Remover March CMPUG 2014 San Jose By Geoffrey Yuxin Hu, PhD, Brizon Inc Lily Yao, PhD, Western Digital Technologies Inc
March 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 CMPUG 2014 San Jose Challenge Poor uniformity of the slurry on the pad Macro- and micro- scratching Residual slurry particles, Al 2 O 3, Colloid SiO 2 etal Trace metals and ions (Cu, Ni, Fe) Recontamination Poor re-rinsibility Etching, Corrosion ( aggressive chemicals, high or low pH, and oxidation)
March 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 SiO 2 Aggregation of particles Wide distribution of particles Macro- and micro- scratching Poor re-rinsibility Residual slurry particles, Al 2 O 3, Colloid SiO 2
March 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 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 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, Al 2 O 3, SiO 2, etc Optimized and Balanced Hydrophobic/Hydrophilic Media
March CMPUG 2014 San Jose Components Special Non-ionic Surfactants Mixed Surfactanized Metal inhibitors And Oxygen Scavenger agents Additional Metal inhibitors And Oxygen Scavenger agents Surfactanized Chelating agents Particle removing agents
March CMPUG 2014 San Jose How it works Hydrophilic Metal inhibitor head Aliphatic Hydrophobic tail Anti-oxidant Hydrophobic Head Ethoxylated Hydrophilic Tail + Briteclean-0+Briteclean-1 Briteclean-0+ : Briteclean-1 = 1:1 In 50X aqueous dilution Briteclean-0+ : Briteclean-1 = 1:1 Bulk solution Phase separation
March 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 Al 2 O 3
March CMPUG 2014 San Jose Briteclean Products Briteclean – 0+Briteclean - 1Briteclean-ACP Pre/Post Cleaning Process YES Slurry Additives YES Storage/Buffer NO YES Application Need to mix with BC-1 or BC-ACP Need to mix with BC-0+ Alone Concentration 1% - 5% 1% - 4%
March CMPUG 2014 San Jose Briteclean Application pH 100% BriteClean-1 100% BriteClean-0+ Diluted 50X in DI H 2 O Recommended Usage: Briteclean-0+/Briteclean-1 = 1:1 Diluted to 1%-5% with DI H 2 O
March 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
SEM Cu Plated Wafer BriteClean Mixture Competitor’s Cleaning Solution
SEM Cu Plated Wafer March CMPUG 2014 San Jose Slurry only Slurry + Brizon products
March CMPUG 2014 San Jose BriteClean Cleaning Solution AluminaNiFe Con Con Competitor Cleaning Solution AluminaNiFe Con Con Different Slurry Cleanability BriteClean vs Competitor Particle Count
March CMPUG 2014 San Jose Particle counts Competitor Cleaning Solution Initial (Pre-) Post Cleaning (Post- Pre) Alumina Tool Tool NiFe Tool Tool BriteClean Cleaning Solution Initial (Pre-) Post Cleaning (Post- Pre) Alumina Tool Tool NiFe Tool Tool
March CMPUG 2014 San Jose Briteclean Application repeatability
March 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 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
March CMPUG 2014 San Jose Acknowledgement NCCAVS Western Digital Brizon Inc