Don H. Rasmussen Chemical Engineering rasmu@clarkson.edu Materials Processing Don H. Rasmussen Chemical Engineering rasmu@clarkson.edu

Outline Characterizing Polymer Surfaces Probing Concentrated Dispersions Making ceramic particles Bonding at interfaces

Characterization of Pads for CMP with Saurahb Jain and S. Subramanian Surface Texture Geometry effects like dishing and thinning Surface Hardness Pad exerted by pad on abrasive particles Wettability Slurry availability at wafer surface

Schematic of Nanoindenter

Force-Displacement Nanoindentation curve Er (GPa) 3.6 Hardness (GPa) 0.35 Power Law Coefficients Execute Fit P=A(h-hf)m Contact Depth (nm) 53.2 Contact Stiffness (mN/nm) 1.4 Max Force (mN) 39.6 Max Depth (nm) 75.1 Contact Area (nm^2) 1.148E+5 Displacement (nm) Force (µN)

Hardness vs. Indentation Depth

Strain Gradient Plasticity Law Based on molecular kink yield mechanism developed by Chong and Lam H0 is the hardness at infinite depth h0 is a material constant

Hardness of OXP3000 Pad

Hardness of OXP3000 Pad

The constants H0h0 and H0 for Different Pad Surfaces H0h0 (GPa nm0.5) H0 (GPa) OXP-milled 1.898  0.351 -0.058  0.038 OXP-smooth 1.702  0.135 -0.019  0.013 OXP-side 1.804  0.466 -0.083  0.050 OXP-reverse 1.208  0.250 0.026  0.023 Experimental Pad-llr1 0.882  0.160 0.005  0.015 Experimental Pad-llr2 1.166  0.076 0.038  0.007 Experimental Pad-hlr 0.853  0.170 0.007  0.016 OXP-reverse (soaked) 1.652  0.016 -0.056  0.015 OXP-smooth (soaked) 2.358  0.252 -0.089  0.029

Probing Concentrated Dispersions with FODLS with Jingxung Fang and Sridhar Sadasivan Measurement of Particle Size Measurement of Particle Concentration

The Variational Problem is ill-posed. I.e. Given the footprints, describe the Tiger.

Theory Is Time Power Spectrum AutoCorrelation Function

Power Spectrum of Scattered Light Lorentzian function: Diffusion Coefficient: (Stokes-Einstein) Scattering vector:

FODLS System Particles He-Ne Laser Coupler PMT Labview DSP VI Slurries Computer Scattered light Optical fiber Reflected light

Single Scattered Signal Single Scattering particles ki q=ks-ki |q| = (4np/l)sin(q/2) q Single Scattered Signal ks Detector

Concentration (wt.%)

Concentration (wt.%)

Measured Particle Size vs Concentration for Silica Slurry #2 Diameter by DLS

Power Spectrum Density vs Concentration for Silica Slurry #2

Making Alumina Particles with C. Brancewicz et. Al. Bayer Liquors as a source of nanoscale aluminas

Making Ceramic Particles with C. Brancewicz

Ternary Phase Diagram for Al(OH)3-NaOH-H2O

Amorphous Aggregates Bayerite

Alumina Particles?

Deformed ceramic particles?

Edax Spectra from Dried Powder

Fibrous Amorphous Sodium Aluminate