Abstract
In this paper, the effect of crystal anisotropy on the evaluation of bonding energy of interface between Cu metal line and insulation layer in LSI was surveyed. Experiment was performed with specimens made of the insulation layer left on the Cu line surface. Dimensions of the specimen were 300x300x480 nm, which was as large as the size of grains. A finite element model of specimen and Cu line was subjected to the elastic crack extension simulation, where Cu crystal was rotated around horizontal axis and vertical axis ranging from 0 to 90 degrees to evaluate the bonding energy. As a result, a range of bonding energy from 2.22 J/m^2 to 2.64 J/m^2 was obtained. On the other hand, in the case of evaluation where Cu was modeled as an isotropic material, 2.32 J/m^2 was obtained. Since much larger range of data scatter was observed in the experiment, it was suggested that anisotropy of plastic deformation should be taken into account to properly explain the fracture behavior of Cu/insulation layer interface.
