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Perpendicularly oriented lamellar forming block copolymers are promising candidates for the fabrication of high aspect ratio nanostructures either by means of direct pattern transfer to the underlying substrate or by sequential infiltration processes. In this work, highly ordered lamellar grains (? > 500 nm) were produced by thermally treating the samples at high temperature (Ttarget > 250 °C) in a Rapid Thermal Processing (RTP) machine. The variation of the lateral order of the nanostructures during the annealing process was investigated in detail, by decoupling the effect of the transients and of the isothermal step of the thermal treatment. Moreover, the self-assembly process was studied as a function of the annealing time and temperature in order to identify the processing parameters that maximize the lateral order avoiding, and at the same time, any degradation of the macromolecules. From this study the activation energy (Ea ~ 55 kJ mol-1) of the lamellar grain coarsening process on featureless substrates was determined. The specific process conditions that promote the self-assembly of lamellar thin films reaching a level of lateral order that is suitable for nanostructure fabrication were established.

The self-assembly (SA) of diblock copolymers (DBCs) based on phase separation into different morphologies of small and high-density features is widely investigated as a patterning and nanofabrication technique. The integration of conventional top-down approaches with the bottom-up SA of DBCs enables the possibility to address the gap in nanostructured lateral length standards for nanometrology, consequently supporting miniaturization processes in device fabrication. On this topic, we studied the pattern characteristic dimensions (i.e., center-to-center distance L0 and diameter D) of a cylinder-forming polystyrene-b-poly( methyl methacrylate) PS-b-PMMA (54 kg mol–1, styrene fraction 70%) DBC when confined within periodic SiO2 trenches of different widths (W, ranging between 75 and 600 nm) and fixed length (l, 5.7 μm). The characteristic dimensions of the PMMA cylinder structure in the confined configurations were compared with those obtained on a flat surface (L0 = 27.8 ± 0.5 nm, D = 13.0 ± 1.0 nm). The an...

A systematic study of the deposition parameters for themetal-organic chemical vapour deposition growth of In-Sb- Te (IST), of interest for phase change memory applications, was performed. Samples were grown on Si/SiO2 and patterned substrates in the (220 divided by 350) degrees C temperature range and working pressure from 35 to 100x10(2) Pa, which resulted in the formation of thin films (down to 30 nm) or IST crystals. The chemical composition of the IST films was mainly dependent on the deposition temperature. We have demonstrated the possibility to obtain a conformal and smooth morphology with improved surface roughness for films grown at 260 degrees C when the substrate surface is treated with the TrisDimethylaMinoAntimony ([N(CH3)(2)](3)Sb) precursor. The IST-based chalcogenide films exhibited different crystalline and partially amorphous phases, which may be favourable for multilevel data storage. The IST growth mechanism was analysed in terms of the structural, compositional and electrical properties.

Ge1-xSbxTey thin films, grown by metalorganic and hot-wire liquid injection chemical vapor deposition in different crystalline phases, are investigated to determine resistivity, carrier density, and carrier mobility in the 4.2-300 K temperature range. It is found that all these chalcogenides exhibit p-type conduction, high carrier density (>2 . 10(20) cm(-3)), and no carrier freeze-out, regardless of composition. Low-temperature mobility data show that both chemical composition and growth technique affect the defect density and, in turn, the carrier scattering mechanisms. In this regard, charge carrier mobility is analyzed according to semi-empirical scattering models and an interpretation is provided.