Molecular systems chemical composition control

To achieve a manufacturable system for sub-0.5-pm patterning, extremely precise control of the molecular properties, structure, composition, and purity of the polymer is required (Table 4). Meeting these requirements provides intellectual challenges in ultrapurification reaction engineering and chemical synthesis. An illustration of the control required in this synthesis process can be found in a negative electron beam resist, GMC. 

We showed that in a mutually catalyzing replication system, the selected state is one in which the number of inactive molecules of the slower replicating species, Y, is drastically suppressed. In this section, we first show that the fluctuations of the number of active Y molecules is smaller than those of active X molecules in this state. Next, we show that the molecular species Y (the minority species) becomes dominant in determining the growth speed of the protocell system. Then, considering a model with several active molecule types, the control of chemical composition through specificity symmetry breaking is discussed. 

The purpose of this chapter is to provide an overview of the chemistry, processing and application of boron-containing preceramic polymers in the BN system. The nonoxide precursor route, also called the Polymer Derived Ceramics (PDCs) route, represents a chemical approach based on the use of air- and/or moisture-sensitive (molecular or polymeric) precursors by means of standard Schlenk techniques and vacuum/argon lines. This precursor route allows the chemistry (e.g., elemental composition, compositional homogeneity and atomic architecture) of molecular precursors to be controlled and tailored in order to provide the ensuing preceramic polymers... 

On this basis, we focused on the sol-gel synthesis and characterization of nanocrystalline copper oxide thin films with the aim to achieve a good control over film chemical composition [66]. In the preparation of such systems, stoichiometry and phase composition represent a major concern, and they can be suitably tailored by a proper choice of the molecular precursors and of the annealing conditions. The chemical composition and copper oxidation state were investigated by X-ray photoelectron spectroscopy (XPS) and X-ray excited Auger electron spectroscopy (XE-AES). Copper oxide thin films (thickness = lOOnm) were produced from copper acetate and were subsequently heated between 100 and 900 °C in different flowing gas atmospheres, i.e. air, nitrogen and forming gas (4% H2 in N2). 

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