Large-Scale Growth of Self-Poled Ferroelectric Rashba Semiconductor α-GeTe(111) Thin Films: A Crucial Step Towards Future CMOS-Compatible Ferroelectric Spintronic Devices.

Chalcogenide ferroelectric Rashba semiconductors (FERSCs) offer a promising route to ultralow-power spin-orbit devices, yet their integration into microelectronics has been hindered by the lack of high-quality films grown using industry-compatible methods. Here, we demonstrate CMOS-compatible synthesis of rhombohedral α-GeTe(111) thin films on 200/300 mm Si wafers using an industrial deposition process based on van der Waals epitaxy, applied to this material class for the first time. Scanning Transmission Electron microscopy and advanced simulations of anomalous X-ray diffraction measurements at synchrotron reveal that films are intrinsically self-poled, exhibiting a robust upward out-of-plane ferroelectric polarization. The growth strategy is universal, enabling high-quality α-GeTe(111) on metals and insulators without compromising structural or ferroelectric performance. Piezoresponse force microscopy confirms reversible 180° ferroelectric switching with performance comparable to molecular-beam-epitaxy benchmarks. This substrate-independent growth strategy represents a decisive step toward the future large-scale integration of FERSCs into functional spin-orbit architectures, with the hope of bridging the gap between Rashba's fundamental physics and microelectronic implementation.