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Self-assembly of cerium oxide nanoparticles to nanorods is reported. Such nanorods have an aspect ratio of 6 with a diameter of approximately 40 nm. The formation of cylindrical supraaggregates and their subsequent growth by preferential assembling of ceria nanocrystallites along the longitudinal direction was proposed to be the probable mechanism of spontaneous self-assembly of nanorods. The supraaggregate formation was facilitated by influencing the local curvature of the micelle surface in the presence of nitrate ions as a precursor solution. The nanorods were characterized using high-resolution transmission electron microscopy with energy dispersive spectroscopy and selected area electron diffraction for their morphology, chemistry, and crystal structure.

Investigations were carried out to understand the effect of hydrogen peroxide as an oxidant and benzotriazole ͑BTA͒ as an inhibitor on the chemical mechanical planarization ͑CMP͒ of copper. Cu-CMP was studied using electrochemistry and removal rate measurements in solutions containing the oxidizer and the inhibitor. In the presence of 0.1 M glycine, the copper removal rate was high in the solution containing 5% H 2 O 2 at pH 2 because of a Cu-glycine complexation reaction. The dissolution rate of Cu increased due to the formation of the highly soluble Cu-glycine complex in the presence of hydrogen peroxide. Addition of 0.01 M BTA in the solution containing 0.1 M glycine and 5% H 2 O 2 at pH 2 exhibited a reduction in the Cu removal rate by the formation of a Cu-BTA complex on the surface of copper that inhibits the dissolution. X-ray photoelectron spectroscopy and secondary-ion mass spectroscopy investigations revealed the formation of a Cu-glycine complex, which aided the understanding of the mechanism of Cu-oxidant-inhibitor interaction during polishing.In the era of miniaturization, the need of the semiconductor industry is primarily to increase the packaging density of devices. The performance of integrated circuits depends highly on the type of interconnect materials. In interconnecting technology, the term RC delay, which is the product of the metal resistance ͑R͒ and the capacitance ͑C͒ of the interlevel dielectric, is a major factor for the selection of materials. Copper is gradually replacing aluminum as an interconnect material because it exhibits not only a superior electrical conductivity and thereby less RC delay, but also high resistance to electromigration. 1,2 Hence, chemical mechanical planarization of copper ͑Cu-CMP͒ has emerged as an important component for the manufacturing of integrated circuits. Usually, the Cu-CMP process consists of several steps such as the removal of the surface layer by mechanical action of the pad and abrasive particles, the dissolution of the abraded particles in the CMP solution, and the protection of recessed areas of the surface by using a corrosion inhibitor. The corrosion process is likely to result in pattern defects; therefore, the chemical composition of the CMP slurry is extremely important. 3 The slurry for Cu-CMP contains chemical components to facilitate the oxidation and removal of excess copper as well as passivation of the polished surface. 4 The use of sodium chlorate ͓NaClO 3 ͔, 5 hydrogen peroxide ͓H 2 O 2 ͔, 6-10 and iron nitrate ͓Fe(NO 3 ) 3 ͔ 8 as oxidizers during CMP was attempted in previous studies. Earlier studies 11,12 have shown the effectiveness of glycine as an inhibitor in preventing corrosion of metals. The inhibiting effect of glycine on Cu-CMP was investigated. [13][14][15] proposed that the formation of an oxide film by H 2 O 2 protects the recess region of copper. On the protruded region, the removal of Cu took place both by mechanical abrasion and dissolution with the formation of water-soluble Cu ϩ2 -glycine chelate in the presence...