US Patent 11177162 Trapezoidal interconnect at tight BEOL pitch

Techniques for forming trapezoidal-shaped interconnects are provided. In one aspect, a method for forming an interconnect structure includes: patterning a trench(es) in a dielectric having a V-shaped profile with a rounded bottom; depositing a liner into the trench(es) using PVD which opens-up the trench(es) creating a trapezoidal-shaped profile in the trench(es); removing the liner from the trench(es) selective to the dielectric whereby, following the removing, the trench(es) having the trapezoidal-shaped profile remains in the dielectric; depositing a conformal barrier layer into and lining the trench(es) having the trapezoidal-shaped profile; depositing a conductor into and filling the trench(es) having the trapezoidal-shaped profile over the conformal barrier layer; and polishing the conductor and the conformal barrier layer down to the dielectric. An interconnect structure is also provided.