Effects of chemical mechanical planarization slurry additives on the agglomeration of alumina nanoparticles II: aggregation rate analysis.
The aggregation rate and mechanism of 150 nm alumina particles in 1mM KNO3 with various additives used in chemical mechanical planarization of copper were investigated. The pH of each suspension was ∼8 such that the aggregation rate was slow enough to be measured and analyzed over ∼120 min. In general, an initial exponential growth was observed for most suspensions indicating reaction-limited aggregation. After aggregate sizes increase to >500 nm, the rate followed a power law suggesting diffusion-limited aggregation. Stability ratios and fractal dimension numbers were also calculated to further elucidate the aggregation mechanism.
NanoEngineering Department, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0448, USA. Electronic address: neil.brahma@gmail.com.
Neil
N
Brahma
NanoEngineering Department, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0448, USA.
Jan B
JB
Talbot
Agglomeration; Aggregation; Aggregation rate; Chemical mechanical planarization; Diffusion limited; Isoelectric point; Nanoparticles; Reaction limited; Zeta potential