Microscratch induced by Chemical Mechanical Polishing (CMP) is a chronic problem to device yield-killing. In sub-14nm device, its criticality becomes more important due to its structural and process complexity. In order to mitigate scratching during CMP process, minimizing abrasive particle size without sacrificing removal rate is the most important parameter. Uniform size distribution of abrasive particles is critical to reduce scratching as well. For this purpose, less than 5nm sized (i.e., nano-sized) cerium hydroxide-based particle (NSC) is utilized as oxide CMP slurry. This size is much smaller than conventionally used calcined ceria slurry (100nm – 200nm in particle size). The slurry that is used in this experiment is designed to have high TEOS selectivity to polysilicon. And the effect of NSC on the microscratch generation is investigated with stop on polysilicon CMP process for so-called ‘dummy gate’ formation and experimental results show more than 80% microscratch reduction compared with process of record (POR) process. Moreover, microscratch size is much smaller than calcined ceria slurry induced microscratch. However, although dramatic microscratch reduction is obtained with NSC, its polishing behavior has not been well understood. In this study, material removal behavior with NSC is explored by a series of experiments involving tribological analysis. 300mm tetra-ethyl-ortho-silicate (TEOS) oxide is used for the experiments, and non-Prestonian TEOS removal behavior with respect to down pressure is observed. At low down force regime, TEOS removal rate is linearly proportional to down force, which is following Preston equation. However, after certain pressure is reached, TEOS material removal rate increases slowly and slope of removal rate becomes smaller. The effect of rotational speed, retainer ring down force, dilution and additive on the removal rate is also explored. TEOS removal rate increase as rotational speed increase is not as sensitive as down pressure effect, and TEOS removal rate is decreased at high retainer ring down force. Experimental results suggest that TEOS removal mechanism by nano-sized cerium hydroxide particle is different from conventionally used calcined ceria particle. Based on the experimental results, this study emphasizes surface reaction as a dominant parameter to determine removal rate rather than mechanical aspect of material removal.