CMOS Compatible Deposition of Multi-Ferroic Films for Tunable Microwave Applications

Different tuning technologies have been used for tunable microwave devices, including semiconductor varactors, ferroelectric based varactors, magnetic field tunable ferromagnetic resonance, MEMS switches, voltage tunable multiferroic heterostructures with voltage tunable permeability or ferromagnetic resonance, etc. However, voltage-tunable inductance, permeability or FMR frequency has not been made possible until recently demonstrated by subcontractor PI Sun et al. In the Phase I of this project, we propose to develop and demonstrate CMOS-compatible low temperature sputtering and spin-coating deposition process for high quality multiferroic thin film heterostructures with large piezo-magnetic coefficient of >5ppm/Oe, low magnetic loss tangent 1 V/cm/Oe. In Phase II of this project, we will demonstrate CMOS compatible magnetic/piezoelectric heterostructures with large magnetoelectric coupling coefficient of > 2 V/cm/Oe, and integrated voltage multiferroic bandstop filters and integrated voltage tunable multiferroic inductors on the basis of the CMOS compatible magnetic/piezoelectric heterostructures developed in Phase I period. This project will enable direct integration of multiferroic devices onto CMOS integrated circuits (ICs), and significantly extend the functionality of CMOS ICs.