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 degreesC and 311 degreesC, Good soft magnetic properties in a range of 40% to 55% volume cobalt with high de resistivity of 500 mu Omega -cm to 100 Omega -cm are measured for films deposited at room temperature. Low intrinsic coercivity, H-ci of 0.76 Oe and susceptibility, chi of 26 in the easy axis direction with quality factor, Q over 100 and saturation flux density, B-s of 0.7 T are obtained.