A 16 GHZ Topological Electrical Circuit Using Interchip Mutual Inductance Fabricated By Dual-Damascene Process

A topological electrical circuit employing mutual inductance, which resonates at 15.5 GHz (Ku-band), is demonstrated for the first time. With the same circuit structure, it exhibits a trivial state by using different circuit parameters. The circuits are composed of copper wiring and fabricated by a dual-damascene process. Flip chip bonding is applied to achieve strong magnetic coupling by reducing the lateral distance between inductors fabricated onto different two dies. The microfabrication technique with the copper wirings realized the higher resonance frequency and low wiring resistance, which will open the way for a wide variety of applications of topological electronics, such as 5G/6G wireless communications and wireless-power-transfer systems.