Magnetic-Multilayered Interconnects Featuring Skin Effect Suppression

A novel concept for a high-frequency, low-loss interconnect with significant skin effect suppression over a wide frequency band is presented. The concept is based on a multilayer comprising thin magnetic (Ni₈₀Fe₂₀) and metal (Cu) layers. The negative permeability of the magnetic layers leads to a near-cancellation of the overall permeability of the multilayer stack. This results in a significant increase of skin depth and thus, a more uniform distribution of the current density and a dramatic reduction of loss within a certain frequency range. Coplanar waveguides built using the multilayer technology show more than 50% loss reduction at 14 GHz compared to their thick Cu-based counterparts.