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In this study, we report for the first time the thin film morphology and property characteristics of a series of adamantane-containing polymers, which were investigated by using synchrotron grazing incidence X-ray scattering, X-ray reflectivity and spectroscopic ellipsometry. The chemically incorporated monomeric and dimeric adamantane units could disturb regular chain packing, ultimately producing amorphous polymers. They further tend to randomize chain orientations even in nanoscale thin films; surprisingly, random chain orientations could be achieved even for thermally-annealed thin films, which are quite different from the in-plane orientations of conventional polymer films being enhanced by thermal annealing. As a result, isotropic optical refractive indices and dielectric constants could be demonstrated even in nanoscale thin films, which are highly demanded for the production of advanced microelectronic devices. Moreover, the adamantane units incorporated into the backbone and as primary side groups could significantly reduce the dielectric constant, refractive index, critical angle, electron density and mass density of polymer. Overall, the positive impacts of incorporated adamantane units are huge on the polymer morphology and properties. All adamantane-containing polymers of this study are suitable materials for advanced microelectronics, which can replace current workhorse dielectrics, such as silicon oxide, silicon nitride, and polyimides, being used in microelectronic devices. Image 1 • Adamantane moieties incorporated in polymer disturb chain packing order severely. • Adamantane units randomize chain orientation even in thermal-annealed thin films. • Adamantane moieties produce zero or near zero birefringence of nanoscale films. • Adamantane units lead zero or near zero anisotropy of dielectric constant of films. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, polyimide surfaces irradiated by an ion-beam for liquid crystal alignment are investigated by using atomic force microscopy, Raman spectroscopy, and spectroscopic ellipsometry. A liquid crystal cell aligned homogeneously through the ion-beam exposure exhibits electro-optic switching behavior similar to that of a rubbing-aligned liquid crystal cell. However, we found that the surface morphology and bonding molecules of ion-beam-treated polyimide surfaces show properties very different from mechanically-rubbed ones. Experimental results show that optical anisotropy of ion-beam-treated polyimide surfaces results in the formation of hydrogenated amorphous carbon-like structure with a short main-chain, while mechanical rubbing has little effect on structural and compositional variations of polyimide layers. [Copyright &y& Elsevier]