Understanding modulus trends in ultra low K dielectric materials through the use of molecular modeling

Molecular modeling has previously been used to study adhesion and surface energy effects of die attach, underfill and viafill formulations, and is currently being used to study the mechanical property trends of the new class of ultra low k nanoporous dielectric materials, NANOGLASS® porous spin-on-glass (SOG) and GX3-P^TM porous organic, being developed within Honeywell. The need to understand material performance from a molecular level is especially understandable when considering the target application in IC fabrication. With such small microstructures, the impact of the molecular mechanical properties imparted by the molecular structure and architecture become more and more important. In addition, we are finding that by understanding the effects of the formulation on the mechanical properties from the molecular level, formulation changes can be planned directly targeted at specific properties. Although we are using many aspects of molecular modeling to help us understand SOG and organic dielectric properties such as density, wetting, solubility and adhesion, for this paper we have concentrated on reporting our observations on modulus. Our studies have found that we can correlate the experimental modulus of these materials very simply with a molecularly derived modulus.