We report the results of electrochemical quartz crystal microbalance (EQCM), and matrix assisted laser desorption ionization (MALDI) time of flight (TOF) mass spectrometry (MS) measurements along with detailed calculations examining the formation of the solid electrolyte interphase (SEI) on battery anode electrodes. EQCM analysis of Au and Sn surfaces in propylene carbonate (PC) and a 1:1 mixture of ethylene carbonate and dimethyl carbonate (EC:DMC) showed major irreversible mass uptake by the electrode surface especially during the first five cycles between +2 and 0.1 V vs. Li/Li + . MALDI-MS on emersed electrodes showed that long chain (m/z = 3000 on PC) oligomerized species were present on Au surfaces in PC and EC:DMC solvents, where oligomerized species formed in PC solutions showed higher mass ratios. The repeating units of the oligomer, visible as oscillations in the MALDI-MS, vary with the type of the solvent and electrode material. Sn surfaces initially showed formation of long chain polymers, but this material was not in evidence on electrode emersed after five cycles, which likely arises as a consequence of the catalytic involvement of Sn in decomposition of initially formed species. Density functional theory (DFT) calculations of cyclic solvent molecules suggested a radical initiated polymerization mechanism and predict oligomer subunits consistent with the experimental results.

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We examine the effects of the nonionic triblock copolymer surfactant Pluronic P103 on three surfaces of different wettability relevant to chemical mechanical planarization (CMP). Two of the surfaces are low-k organosilicate glass (OSG) films, Coral and Black Diamond; the third is a silica surface. Atomic force microscopy (AFM) force curves were used to probe the forces over each surface in solutions of P103. Each surface was also examined in potassium sulfate solutions to investigate the effect of ionic strengths. The AFM force curves show that both P103 and potassium sulfate eliminate adhesive forces at sufficiently high concentrations. DLVO theory was used to fit the AFM approach curves in order to calculate estimated surface potentials. Interestingly, the force curves suggest that molecular orientation of the P103 is different on surfaces of different wettability. The P103 was found to adopt a flat conformation on the hydrophilic silica surface while more extended structures formed on the more hydrophobic Coral and Black Diamond surfaces. These results provide a molecular-level understanding to aid the development of CMP formulations that will provide greater control on dielectric removal rate and reduce the overall non-uniformity in film thickness across the wafer.

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