A novel study was made of electromigration phenomena in Cu interconnects using a multi-scale simulator that consisted of a combination of a device scale simulator based upon a kinetic Monte Carlo method and an atomic scale simulator based upon ultra-accelerated quantum chemical molecular dynamics. First demonstrated was simulation of the lifetime of Cu interconnects using a device scale simulator and setting some suitable kinetic Monte Carlo probabilities for void movement according to the regions (grain, grain boundary) into which it could be divided. The simulated values were shown to be in good agreement with experimental values. In an attempt to connect device-scale studies to quantum chemistry, an atomic-scale simulator was developed. In this simulation, the electron wind force was evaluated by using a previous electrical conductivity prediction simulator based upon the kinetic Monte Carlo method, using electronic states from tight-binding quantum chemical calculations. Using this atomic-scale simulator under the conditions of 475K and 2.5 x 1010A/m2 current density, it was possible to simulate successfully the migration of a Cu atom from a lattice site to a vacant site by evaluating the electron-wind force.

Development of a Multi-Scale Electromigration Simulator Based on a Combination of Ultra Accelerated Quantum Chemical Molecular Dynamics and Kinetic Monte Carlo Methods Application to Cu Interconnects Lifetime Simulation. H.Tsuboi, A.Kato, H.Sato, F.Hasekura, S.Oda, H.Setogawa, C.Abe, A.Chutia, C.Lv, Z.Zhu, R.Miura, A.Suzuki, R.Sahnoun, M.Koyama, N.Hatakeyama, A.Endou, H.Takaba, C.A.Del Carpio, R.C.Deka, M.Kubo, A.Miyamoto: Japanese Journal of Applied Physics, 2009, 48[4-2], 04C020