The effect of pad surface texture on dielectric and copper removal rates was studied theoretically and experimentally by investigating the fluid behavior of the slurry layer using methodologies similar to those found in tribological investigations of fluid bearings. It is shown that new nonfoamed hard plastic pads with intricate groove patterns are critical in modulating removal rates. Removal rate results of dielectric chemical mechanical polishing were in close agreement with model predictions for several of the groove designs tested. Combined patterns, consisting of spiral and logarithmic grooves, were shown to impact several key attributes of the dielectric and copper processes in terms of slurry retention, hydrodynamic pressure, tribological mechanism, and material removal rates.

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An innovative dilatancy polishing pad of which characteristics are controlled with processing conditions is proposed to establish high-efficiency, high-quality polishing of hard-to-machine materials for next-generation high-power devices. To make the best use of the property of the dilatancy pad, a highly durable polishing machine which enables high-pressure, high-speed, and immersed polishing was developed. Dilatancy properties were evaluated for various viscoelastic materials to select appropriate materials for a pad. The selected viscoelastic material was mixed with a special filler and abrasive particles, and integrated into a conventional polishing pad to form a dilatancy pad. Application of the dilatancy pad to polishing of SiC realized a smart polishing which achieves both high efficiency and high quality in any processing conditions. In addition, it was demonstrated that the processing conditions could be selected for the purpose of each polishing step, i.e. mid- to high-speed conditions for high-efficiency polishing and low-speed condition for high-quality finishing. A newly developed highly durable polishing machine is capable of achieving wide range of processing conditions. To avoid overheating under high load conditions, the machine can polish a work piece in slurry fluid. The material removal rate using the dilatancy pad showed superlinear dependence on the rotation speed, which outperforms the conventional polishing following the Preston's law. This innovative process can significantly reduce the polishing time of hard-to-machine materials for next-generation semiconductor devices.

High-efficiency and high-quality chemical mechanical polishing (CMP) of silicon carbide (SiC) substrates was achieved using slurries prepared with manganese oxide (MnO2，Mn2O3) particles. Experimental results showed that the oxidation-reduction potential and zeta potential of these manganese (Mn)-based slurries decreased with increasing pH. For alkaline pH values (> 7), MnO2 particles were converted into strongly oxidizing MnO42- ions that promoted interfacial chemical reactions during CMP, thereby increasing the material removal rate. Observation and analysis of the SiC substrate surface showed that the surface roughness (Ra) reached 1 nm after polishing, but slight surface scratches remained. The binding energy of elemental oxygen (O) and Mn (O1s and Mn2p) indicated that the atoms on the substrate surface underwent an oxidation reaction, which weakened the Si-C molecular bond and thus increased the material removal rate.