Effects of dielectric material and linewidth on thermal stresses of Cu line structures

Thermal stresses of Cu line structures of 0.4 and 0.2 μm linewidth integrated with fluorinated silicon oxide SiOF and two kinds of low k dielectrics, carbon doped oxide CDO and organic polymer SiLK™, were measured using x-ray diffraction. Finite element analysis was performed to evaluate the stress behavior of the Cu lines and to examine the effect of scaling in linewidth. After verification with the measured Cu line stresses, FEA was extended to evaluate the stress behavior of the low k dielectrics. The confinement effects on thermal stresses due to low k dielectric on Cu lines and Cu lines on the dielectric are compared and discussed.