Wake-Up-Free Complementary Metal-Oxide-Semiconductor-Compatible Multiferroic Heterostructures for Application in Magnetoelectric Spin-Orbit Devices.

The integration of multiferroic materials into complementary metal-oxide-semiconductor (CMOS) technology presents an exciting frontier in nanoelectronic research. These materials enable energy-efficient, non-volatile functionalities, which are highly sought properties for next-generation devices, particularly for synapses and neurons in artificial intelligence systems. To facilitate seamless integration into modern nanoelectronics, fabrication compatibility of CMOS processes is required. This work demonstrates CMOS-compatible multiferroic heterostructures consisting of hafnium zirconium oxide and cobalt-platinum thin films on 12 in. Si wafers, exhibiting wake-up-free remanent polarization of 2Pr ≈ 30 μC/cm2 and perpendicular magnetic anisotropy with an effective magnetic anisotropy energy of Keff ≈ 0.13 mJ/m2 on a thin-film level. Insights into crystallization and diffusion during BEOL-compatible processing are obtained through structural investigation of the polycrystalline stacks. Qualitative indications for manipulation of the magnetic anisotropy are shown utilizing advanced scanning probe microscopy methods, suggesting the potential for application in scalable, CMOS-compatible magnetoelectric spin-orbit devices.