There are many issues in the area of microscale heat transport directly related to a broader description and understanding not only of heat transport, but also micro-and macro-electrodynamic behavior resulting from irregularity and heterogeneity of matter at the atomic and nanoscale level. We propose to use our experience in the development of hierarchical theory and modeling to address the issue of heat generation and transport in semiconductors. This process will be studied using scaled local-non-local hierarchical theory of description phenomena on each level of physical phenomena and on the upper scale level of the process. The importance of controlling dissipation within semiconductor devices is well known. Because the physics and modeling tools needed for application to phenomena at the nanoscale are fundamentally different than those for conventional continuum media, non-local hierarchical technology of volume averaging theory (VAT) will be the basis for the proposed effort. These techniques were critical tools in developing a scaling modeling methodology for hierarchical continuum physics of heat transport, fluid mechanics and other areas and were the basis for variational parameter assessment and scaled phenomena optimization of heat exchange devices, particularly the optimization of the powerful semiconductor heat dissipation coolers.
Using VAT based tools, means of describing, modeling along with experiment over the two - and three scale hierarchical semiconductor material structures will be developed to describe their physical properties. The modeling effort would focus on developing techniques and tools needed to describe the interaction of local- non-local (nanoscale-microscale) observable data and their theoretical description. The objective of the proposed project is to improve the developed descriptions of phenomena that better explain heat generation during the normal operation of semiconductor devices with the intention to find ways to reduce the amount of heat generated. This goal will be achieved using the techniques developed for describing the connection and intercommunication of the phase - interface - phase media properties between the neighboring phases and scales and will include thermal, electrical phase and effective conductivities as well as nanoscale and atomic scale features, like wave scattering effecting heat rate generation during the normal semiconductor device operation. The unique features of a VAT description of phenomena like collision and scattering, which are of great influence on the transfer of energy at the nanoscale and multicrystalline scale levels, allows the connection to be made between the atomic-nanoscale material structure and its modeling features to the heat generation rate.