2D Magnetic Inductors for DC-DC Converters on Glass Interposer

On-chip integration of voltage regulators could significantly improve performance of 3D ICs. However, integration of voltage regulators is difficult due to the size of inductors. To reduce inductor size, thin-film magnetic materials on glass substrates, which amplifies inductance values, should help on-chip inductor integration. Using Ni45Fe55 and Co80P20 magnetic materials, we successfully fabricated 2D core and coreless copper inductors, on both glass and silicon substrates for comparison purposes. Inductors on glass exhibit better performance than the ones fabricated on silicon. An inductance density of up to ~30 nH/mm² was reached.