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We developed a novel method to synthesize the polystyrene-SiO2 composite abrasive with raspberry structure. The SiO2 nanoparticles were embedded by the polystyrene microsphere. This raspberry-like composite abrasive had lots of advantages for CMP abrasive, for example, the hardness of composite abrasive could easily be controlled by the proportion of SiO2 and the cushioning effect of soft polystyrene core could decrease the excessive mechanical damage caused by hard silica abrasive. Moreover, this structure made sure the stability of composite abrasive in the polishing process. The shape of composite particles was sphere and monodisperse. The size of polystyrene-SiO2 could be controlled in the range from 50 ~ 300 nm by adjusting the amount of styrene monomer. The removal rate in polishing test depended on the proportion of SiO2 and hardness of composite abrasive.

In the chemical mechanical planarization (CMP) process, slurry particle size is important because large particles can cause defects. Hence, selection of an appropriate particle measuring system is necessary in the CMP process. In this study, a scanning mobility particle sizer (SMPS) and dynamic light scattering (DLS) were compared for particle size distribution (PSD) measurements. In addition, the actual particle size and shape were confirmed by transmission electron microscope (TEM) results. SMPS classifies the particle size according to the electrical mobility, and measures the particle concentration (single particle measurement). On the other hand, the DLS measures the particle size distribution by analyzing scattered light from multiple particles (multiple particle measurement). For the slurry particles selected for evaluation, it is observed that SMPS shows bi-modal particle sizes 30 nm and 80 nm, which closely matches with the TEM measurements, whereas DLS shows only single mode distribution in the range of 90 nm to 100 nm and showing incapability of measuring small particles. Hence, SMPS can be a better choice for the evaluation of CMP slurry particle size and concentration measurements.

The purpose of this paper is to investigate the effect of diamond grit during chemical mechanical polishing (CMP) process. CMP is the most important for planarization of wafer surface in semiconductor manufacturing. During polishing process, the wafer surface and the pad are contacted with the slurry. There are various contact area, which are wafer-pad aperture and conditioner-pad aperture, and so on. Between diamond grits and pad, those contacts can affect wafer polishing process. Conditioner of CMP dresses pad surface to maintain CMP pad surface constant. Otherwise, CMP pad will be degraded out quickly after several wafer process. Shape of diamond pattern and their effect on pad property were reported, but there are no researchers related novel diamond conditioner. In this study, we experiment CMP process by using different conditioners and analyze wafer polishing property as conditions.