Evaporatively deposited Co-MgF2 granular materials for thin-film inductors

Co-MgF2 granular thin films prepared by thermal evaporation, are reported. The fabricated materials show promise as high-frequency, low-loss cores for microfabricated magnetic devices in microprocessor power delivery applications. Transmission electron microscopy (TEM) reveals Co grains of about 3.2 nm embedded in a MgF2 matrix 1 to 2 nm wide. Films were prepared with 20% to 89% volume cobalt at substrate temperatures between - 21°C and 311°C. Good soft magnetic properties in a range of 40% to 55% volume cobalt with high dc resistivity of 500μΩt-cm to 100 Ω-cm are measured for films deposited at room temperature. Low intrinsic coercivity, Hci of 0.76 Oe and susceptibility, X of 26 in the easy axis direction with quality factort, Q over 100 and saturation flux density, Bs of 0.7 T are obtained.

Duke Scholars

Author Kip Coonley