Polypyrrole ͑PPy͒/ion-conducting polymer electrolyte ͑PE͒ composites are prepared by in situ electropolymerization of pyrrole in a solvent-free PE matrix which is formed by photocross-linking of triacrylated poly͑ethylene oxide-co-propylene oxide͒ ͑TA͒. X-ray photoelectron spectroscopy measurements reveal the gradient structure at the PPy/PE interface where PPy is formed with the concentration gradient. For the composite film, a facile electron transfer across the PPy/PE interface is demonstrated by a cyclic voltammogram for the doping-undoping process, and a decrease in the charge-transfer resistance at the interface is proved by an electrochemical impedance analysis. This is in marked contrast to a combined bilayer film of PPy and TA-based PE for which an electron transfer across the interface between two polymer films is not clearly observed. The composite exhibits charge-discharge performance, which suggests a possibility of fabricating solid-state batteries composed of conductive polymer electrode/ion-conductive PE/Li by one-step electrolysis.Polymer electrolytes ͑PEs͒ offer many advantages over conventional liquid electrolytes in their application to practical electrochemical devices. 1 The most important and promising application of PEs is lithium secondary batteries, and one of the major driving forces behind the research and development of solvent-free PE systems has been the potential for making safe lithium batteries. Many researchers have focused on the enhancement in the ionic conductivity of solvent-free ion-conducting PE systems at ambient temperature. 2-6 As a result, PEs with room temperature conductivity higher than 10 Ϫ4 S cm Ϫ1 have been achieved. However, the interpenetration between electrodes and solid PEs does not occur as effectively as that between electrodes and liquid organic electrolytes, and thus the effective charge transfer at the electrode/PE interface is another essential factor in realizing high-performance solid-state lithium secondary batteries.Polyheterocyclic conducting polymers such as polypyrrole ͑PPy͒ and polythiophene have been proposed as new positive electrodes in lithium rechargeable batteries. 7-9 The combination of these conducting polymer electrodes with PEs made it possible to design batteries which could be shaped to fit devices or could be an integral part of devices. However, due to the poor interpenetration of two classes of polymers, efficient charge transfer across the two polymer interfaces could not be attained for combined films of a polyethylene oxidebased PE and polyacetylene or PPy. [10][11][12] The in situ electropolymerization of pyrrole ͑Py͒ within another polymer matrix has been used to prepare conductive polymer blends. 13 This method is applicable also to solvent-free PE systems, and the resulting PPy/PE composite revealed doping-undoping activity in solid state. 14,15 Because the charge-discharge process of these conducting polymer electrodes is accompanied by the doping-undoping of anions, effective ion transport across the interface is importa...

An abrasive-free polishing (AFP) solution for chemical-mechanical planarization (CMP) of copper films on semiconductor wafers has been developed to overcome such disadvantages of conventional CMP as dishing, erosion, Cu and oxide loss, and microscratching. Electrochemical methods are an effective way of understanding the role of each chemical component in the AFP solution in order to optimize its performance. Analysis of the reaction layer of Cu elucidates the reasons for the excellent results that have been obtained. By applying the AFP solution for Cu CMP in combination with a slurry for CMP of the metal barrier layer, seven-level multilayer Cu interconnections can be successfully fabricated.

In order to reduce microscratches and obtain minimized dishing and erosion, we have developed new abrasive-free Cu CMP slurries. During the development of these slurries, some electrochemical examination was performed. The most effective knowledge was obtained through the analysis using rotary Cu disk electrode under pressure. On the basis of these studies, new abrasive-free Cu CMP slurries with a high removal rate and excellent planarity were designed and developed. The mechanism of reducing dishing and erosion was also discussed.Mater. Res. Soc. Symp. Proc. Vol. 991

To develop high signal speed semiconductor LSIs, Cu interconnection is one of the most important requirements. In the fabrication of Cu interconnections using CMP method, minimized dishing, erosion and reduction in micro-scratches are large issues to be realized. We performed a research for superior properties of Cu CMP. Finally, we succeeded in developing Abrasive Free (AF) Cu slurry suitable for these requirements.We also developed slurry for barrier (TaN) with a high selectivity between TaN and SiO2 of 50 to reduce oxide (SiO2) loss. This reduced oxide loss is directly related to obtaining a controlled circuit resistivity.By applying these two kinds of slurries, ULSIs with multilevel Cu interconnects and excellent reliabilities were obtained.

Abrasive-free Cu CMP solutions have been developed to reduce micro-scratches and obtain minimized dishing and erosion properties. During the development of the solutions, some electrochemical examinations were performed. One of the most instructive knowledge was obtained through the Tafel plot. Other attractive data were obtained through Cu complex film analysis. On the basis of these studies were developed and released newly formulated abrasive-free Cu CMP solutions with a high Cu removal rate and excellent topography performance. Mechanism of polishing by applying abrasive-free Cu CMP solutions is also discussed in this paper.