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We have studied the characteristics of the mixture of HNO3 , HF , and H2O2 chemicals called the controlled slight etch (CSE) solution as an effective wafer cleaning solution. The silicon etch rate in the CSE solution was not dependent on HF concentration of the solution, while that in a mixture of HNO3 and HF was linearly dependent on HF concentration. The CSE solution reduced the surface concentrations of Fe and Cu ions below a concentration of 1010 normalatom/cm2 on the intentionally contaminated wafers and suppressed average surface microroughness increase in comparison to slight etch (SE) solution. X‐ray photoelectron spectroscopy (XPS) showed that the CSE cleaning does not leave chemical oxide on the surface. The average breakdown field for the CSE‐cleaned sample was 11.5MV/normalcm . We explained the etching mechanism that the H2O2 species in the CSE solution slows down the rate of oxidation reaction of the silicon wafer by interrupting autocatalytic reaction of HNO3 .

A polishing pad plays an essential role in determining the chemical mechanical planarization (CMP) performance such as removal rate, planarization, and defectivity. Further, it is important for the polishing pad to maintain good CMP performance throughout its lifespan. In order to achieve high performance and durability, a hole-type pad was suggested as an alternative to the conventionally used pore-type pad. In this study, the effect of the hole density on the CMP performance was examined for a hole-type pad. Surface characterization of the hole-type pad showed that the hole density corresponded to the contact ratio between the pad and the wafer, and therefore, the contact characteristics could be controlled by a hole fabrication process. The experimental results showed that the number of holes play a key role in determining CMP performances. The removal rate decreased with an increase in the hole density. The level of dishing showed an increase with the hole density. The number of CMP scratches decreased at higher hole densities. Higher contact ratio and the presence of large particle trap sites explain the lower trend of the micro-scratch observed. An important advantage of the hole-type pad is that it retains the surface structure as CMP continues, which implies contact behavior is maintained.

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