Integrated circuits with single core inductors and methods for producing them are provided. Embodiments include forming a trench in a dielectric layer; forming a first metal-oxide hard mask by disposing a metal hard mask and an oxide hard mask over the dielectric layer and in strips in the trench; forming metal line trenches through the first metal-oxide hard mask and into the first dielectric layer on opposite sides of the inductor trench and first vias; filling the first metal line trenches, first vias, and trench; forming another dielectric layer and a second metal-oxide hard mask over the filled trench; forming a second trench through the second metal-oxide hard mask and into the second dielectric layer and second metal line trenches and second vias; and filling the second metal line trenches, second vias, and second trench.