Methods and conductive interconnect structures are provided for preventing
cracks in a dielectric layer on a substrate. Substantially half cylindrical or
cylindrical trench openings are formed within at least one dielectric layer, which
are then filled with a high conductivity metal for forming substantially half cylindrical
or cylindrical wires. The rounded bottom portions of the substantially half cylindrical
wires, or the rounded bottom and top portions of the substantially half cylindrical
wires, avoid any propagation points for starting cracks in the dielectric layer,
as compared to conventional rectangular conductors having angled edges, which in
fact are propagation points for initiating cracks. The substantially half cylindrical
or cylindrical wires also reduce the line-to-line capacitance between neighboring
wires, substantially eliminate any high stress points in the dielectric layer,
reduce mechanical stresses induced on the IC and increase the overall mechanical
strength of the IC.