A schematic illustrating a cross section through a typical dual-damascene copper interconnect structure. The thickness of the various layers is not to scale.
(a) A schematic diagram illustrating the patterned line structures used in experimental measurements. (b) A cross section through the experimental test structure.
Unit cell used in finite element computations.
Measured stress relaxation in an array of damascene copper lines. Results are shown for films passivated with SiN and SiC, as well as for unpassivated lines; and are the components of stress parallel and transverse to the lines, respectively.
Predicted stress relaxation in the idealized interconnect structure as a function of time. (a) Ideal (100) texture and (b) ideal (111) texture.
The influence of changes in elastic modulus of the passivation. The Cu/cap interface has a diffusivity of for both simulations.
Diffusion paths that cause stress relaxation.
The influence of copper grain-boundary diffusivity on the stress relaxation in patterned lines. Results are shown for isotropic grains with Young’s modulus and Poisson’s ratio (a) . and (b) .
Influence of Cu/Ta interface diffusion on stress relaxation. Results are for isotropic copper grains, other parameter values are listed in Tables I–III. (a) and (b) .
Predicted stress relaxation in lines with various grain sizes: (a) and (b) .
The stress relaxation measured in interconnect structures with CDO dielectric.
Predicted stress relaxation in an interconnect structure with dielectric modulus 4.7GPa: (a) Ideal (100) texture and (b) ideal (111) texture.
Dimensions used in modeling. Grain size, .
Material properties used in numerical simulations.
Estimated values for interface diffusivities.
Article metrics loading...
Full text loading...