Significantly Enhanced Inductance and Quality Factor of GHz Integrated Magnetic Solenoid Inductors With FeGaB/ ${\rm Al}_{2}{\rm O}_{3}$ Multilayer Films

We report new high quality factor (Q) integrated GHz magnetic inductors based on solenoid structures with FeGaB/
${\rm Al}_{2}{\rm O}_{3}$
multilayer films, which show significantly enhanced inductance and quality factor at GHz frequencies over their air core counterparts. These inductors show an excellent high-frequency performance with a wide operation frequency range 0.5–2.5 GHz, in which the inductance is flat and the peak quality factor can reach
${\sim}{\rm 20}$
. The inductance of the magnetic inductor shows
${>}{100\%}$
enhancement compared with that of the same size air core inductor. These novel GHz inductors with high inductance and Q enhancement show great promise for applications in radio frequency integrated circuits.