A semiconductor device has a first coil structure formed over the substrate. A second coil structure is formed over the substrate adjacent to the first coil structure. A third coil structure is formed over the substrate adjacent to the second coil structure. The first and second coil structures are coupled by mutual inductance, and the second and third coil structures are coupled by mutual inductance. The first, second, and third coil structures each have a height greater than a skin current depth of the coil structure defined as a depth which current reduces to 1/(complex permittivity) of a surface current value. In the case of copper, the coil structures have a height greater than 5 micrometers.The first, second, and third coil structures are arranged in rounded or polygonal pattern horizontally across the substrate with a substantially flat vertical profile.