Synthesis And Dielectric Properties Of Pyridine Quaternary Ammonium Salts

The advancement of semiconductor integrated circuit technology has promoted therapid development of new materials and technologies. The technology itself also rankedthe semiconducting sector a vital contributor to the industry.The signal propagation delay, interference between lines and power dissipationwhich caused by the decreasing of width, the continuous increasing of transistor densityand the resistance-capacitor (RC) delay, become an unavoidable issue of integratedcircuit technology development.In addition to the use low-resistance metals such as copper as the substituent ofaluminum, the primary solution to reduce interconnect delay, crosstalk and powerconsumption is to minimize the parasitic capacitance (delineate as C). As C isproportional to the dielectric constant (k), an indirect way to reduce this value would bethe introduction of low k dielectric film as the replacement of the conventional SiO2(k≈4).Further development of low k dielectric materials has become the key tocomplement the shortcomings of the commonly used dielectric polymers and porousmaterials. This thesis studies the molecular configuration and packing on the outcomeof dielectric constant and the inter-conversion of the two material morphologies.The thesis contains the following three parts:1) The first part reviews the progress of low k materials, the mechanism andapplications of materials with/without SiO2dopant, and nano-materials. Thispart also summaries the contemporary ways to low k values and the preparationmethod low k films.2) The second part describes the solvothermal synthesis of isomeric pyridiniumsalt pair with different crystal packing modes: v-C12H14I2N2(1) andp-C12H14I2N2(2). The synthesized compound was characterized by means of TGA, UV-Vis and temperature-dependent PXRD. The effect of the crystalpacking mode on the dielectric properties was discussed and interpreted withthe assistance of additional theoretical data. The controlled inter-conversion ofthe two packing mode of the material is also discussed.3) The third part describes the designed synthesis of four additional pyridiniumsalts (compound3-6) and characterized by single crystal structures in additionto IR, elemental analysis. The possibility of low k values of these materials isalso elaborated through the detailed structural analysis.