Multifunctional Slurry Formulation

1
Multifunctional Slurry Formulation - Chemical
Mechanical Polishing (CMP) -
Brij M. Moudgil Department of Materials Science
and Engineering and Particle Engineering Research
Center University of Florida, Gainesville, FL
32611 Florida Research Consortium, Tech
Transfer Consortium May 17-18, St. Petersburg, FL
2
Scientific Team
FACULTY Dr. Brij M. Moudgil - Distinguished
Professor of Materials Science and Engineering,
Director of the Particle Engineering Research
Center (PERC), Member of the National Academy of
Engineering Dr. Chang-Won Park Professor of
Chemical Engineering, Co-Team Leader Dr. Yakov
Rabinovich Research Professor, PERC Dr. Dinesh
O. Shah Professor of Chemical Engineering
Anesthesiology, Director of Surface Science and
Engineering Center Dr. Rajiv Singh Professor of
Materials Science and Engineering, Co-Team
Leader Dr. Susan Sinnott Assoc. Professor of
Materials Science and Engineering FORMER GRADUATE
STUDENTS Drs. Josh Adler (intel), Alex Patist
(Cargill), Uday Mahajan (Intel), Byron Palla
(TI), Bahar Basim (Intel), Pankaj Singh
(Unilever), Kyo-Se Choi (Samsung), Wonsep Choi
(Samsung), Kuide Qin (Praxair) CURRENT GRADUATE
STUDENTS Suresh Yeruva, Scott Brown, Jeramaih
Abiade, Kunal Shah, Kwang-Ho Bu
3
WHY CMP SLURRY DEVELOPMENT ?
Slurry market sector continues to increase almost
20 per year despite semiconductor market
fluctuations
4
WHAT IS CMP ?
Down Force
Slurry
Wafer Carrier
Polishing Pad
Wafer
Platen

• Chemical action from aqueous media
• Mechanical action from abrasives

5
Example Aluminum/Tungsten Interconnects

• Silica deposited on metal circuits

• Silica is planarized and interconnects etched

• Interconnects filled with tungsten and planarized

• Circuits printed and process repeated

6
Features of the CMP Process

• Scratches
• Residual abrasive particles
• Delamination at weak interfaces
• Stress cracking

• CMP achieves global planarity enabling multi
  level metallization.

7

• CMP Performance Criteria (specifications)
• Material Removal Rate (2000-7000 Å/min)
• Surface Quality
• Surface Roughness (lt 2 nm RMS)
• Maximum Depth of Scratches or Pits (lt 40 nm)

8
Technology Multifunctional Slurries

• Processing scheme for formulation of
  nanoparticulate slurries that are multifunctional
  and stable under extreme processing conditions,
• Commercially available surfactants (soaps) are
  used as reagent schemes,
• Rheology, and lubrication polishing can be
  controlled independently in a given system to
  optimize slurry performance

NOVELTY Science based
control of particle-particle, and
particle-substrate
interactions in CMP
9
Technology Status
Materials and Methods for Control of Stability
and Rheological Behavior of Particulate
Suspensions US Patent Application Docket
UF-245XC2
Proof of Concept Experiments Nanotribology
Results
10
Technology Status Polishing Results
5000
4000
0.1 M CaCl2 32 mM C12TAB
Material Removal Rate (A/min)
0.24 M CaCl2 32 mM C12TAB
3000
0.1 M CaCl2 32 mM C12TAB
0.2 M CaCl2 32 mM C12TAB
0.6 M NaCl 32 mM C12TAB
32 mM C12TAB
Baseline
2000
1000
0
11
Advantages Over the
State-Of-The-Art

• Current industrial strategies
• Point of use administration of chemical reagents
  
• - reduces time for coagulate formation
• - artifacts due to poor dispersion still
  present (defects etc.)
• Multiple Slurries used
• - poor control over stability and friction
  (variable stability and removal rates)

• Robust dispersion and improved rheology of
  slurries with high solids loadings.
• Dispersion in saturated salt solutions other
  extreme conditions
• Significantly reduced shear thickening in high
  concentration (gt30wt) slurries (pumping and
  transport).
• Tunable Frictional properties
• lubrication and wear can be turned on and off
  and adjusted as needed to optimize polishing

12
Potential Commercial Impact
Products Polishing Slurries for Future
Electronic Materials - Tunable Low Stress
Slurries for low K dielectric polymer CMP, -
CMP Slurries for MEMS and NEMS Devices Novel
Particle Systems for optimal performance (e.g.
Advanced Ceramics, High Speed Coatings, Composite
materials, Pigments, etc.) Processes
Improved Process Control Reduction of Equipment
Wear Energy Expenditures
Cost effective science based development of
dispersion and lubrication reagent schemes

13
Other Target Industries

• Microelectronics manufacturing applications,
  especially CMP inspired the proposed slurry
  formulation technology
• Dispersed slurries/suspensions are of major
  significance also in the following industries
• Pharmaceutical - Abrasives
• Paints Coating - Food
• Ceramic/Mineral Processing - Pulp Paper

14
What is Next?

• Conduct Scale-up Polishing Tests (8 wafer
  platform) for optimization and generating
  cost estimates
• Develop Selective Tunable CMP Slurries
  (single step polishing)
• Expand Knowledgebase to Other Materials
• Softer materials for MEMS NEMS
• applications
• Transfer Technology to Other Applications
  Pigments, High speed coatings etc.

15
Point of Contact
Brij M. Moudgil, Director, PERC
(bmoudgil_at_erc.ufl.edu) OR Victor
Jackson, PERC Associate Director for Industrial
Collaboration Technology Transfer
(vjackson_at_erc.ufl.edu) 205 Particle Science and
Technology Bldg, PO Box 116135 Gainesville, FL-
32611-6135 USA [phone] phone (352)
846-1196 fax
16
Acknowledgments
The authors acknowledge the financial support of
the Particle Engineering Research Center (PERC)
at the University of Florida, The National
Science Foundation (NSF) (Grant EEC-94-02989),
and the Industrial Partners of the PERC for
support of this research. Any opinions, findings
and conclusions or recommendations expressed in
this material are those of the author(s) and do
not necessarily reflect those of the National
Science Foundation.