Aerosol Deposition of Yttrium Iron Garnet for Fabrication of Ferrite-Integrated On-Chip Inductors

We have employed aerosol deposition (AD) to deposit 39 μm thick polycrystalline films of yttrium iron garnet at room temperature onto sapphire at a rate of 1-3 μm/min as an initial investigation of utilizing AD for fabricating ferrite-integrated on-chip inductors. We characterize the structural and magnetic properties of the as-received starting powder, as-deposited film, and a pressed puck formed from the starting powder. Results show that the films are comprised of randomly oriented polycrystalline grains with structural and magnetic properties that closely resemble that of the starting powder. Results from coating a gold single-turn inductor show an increase in inductance of 79% up to ~300 MHz without affecting the Q-factor. These results demonstrate AD as a promising technique for depositing thick ferrite films at high deposition rates for low-temperature fabrication of ferrite-integrated on-chip inductors.