Petascale simulation of electron currents in nanoscale interconnects*

The on-die interconnect has become the dominate heat generating source in a modern chip. As the transistor size gets even smaller, or the device architecture changes to 3D stacking, the interconnect problem will only become worse. Petascale high performance computing is used to study the current flow in such a nanoscale interconnect. Ab initio simulation is used to construct the Schrodinger’s equation for a system with tens of thousands of copper atoms based on linear scaling density functional theory. The electron scattering states are calculated using a linear combination of perturbation induced “system” states. The direct viewing of the intensity of such scattering states (current) will show some insights for where the heat is generated. Future calculation of electron-phonon coupling will allow the calculation of heat generation. The challenges of the simulations will be discussed, as well as the computational issues in such large scale simulation.