Modelling microstructure development in trench-interconnect structures

The effects of surface and interfacial energies and trench geometry on microstructure evolution in damascene-processed interconnect structures are modelled. Grain growth and texture evolution are shown to depend on the magnitude of surface and interfacial energy variations with crystallographic orientation and with trench aspect ratio. Grain texture evolution in high aspect ratio trenches is driven by the minimization of grain sidewall interfacial energy, whereas the crystallographic evolution of grains within low aspect ratio structures is determined by more typical surface and lower interface energy minimization considerations. Comparisons are made to recent experimental results which characterize the development of crystallographic texture and grain size in damascene-processed interconnects.