| 摘要 |
A nanoparticle which includes a multi-armed core and surface decoration which is attached to the core is prepared. A multi-armed core is provided by any of a number of possible routes, exemplary preferred routes being living anionic polymerization that is initiated by a reactive, functionalized anionic initiator and epsilon-caprolactone polymerization of a bis-MPA dendrimer. The multi-armed core is preferably functionalized on some or all arms. A coupling reaction is then employed to bond surface decoration to one or more arms of the multi-armed core. The surface decoration is a small molecule or oligomer with a degree of polymerization less than 50, a preferred decoration being a PEG oligomer with degree of polymerization between 2 and 24. The nanoparticles (particle size <=10 nm) are employed as sacrificial templating porogens to form porous dielectrics. The porogens are mixed with matrix precursors (e.g., methyl silsesquioxane resin), the matrix vitrifies, and the porogens are removed via burnout. Greater porosity reduces the dielectric constant k of the resulting dielectrics. The porous dielectrics are incorporated into integrated circuits as lower k alternatives to silicon dioxide.
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