Integration and Electrical Properties of Ferroelectric Hf0.5Zr0.5O2 Thin Film on Bulk β-Ga2O3(-201) Substrate for Memory Applications

Metal–ferroelectric–insulator–semiconductor (MFIS) structures with wide bandgap semiconductors are promising for high temperature, radiation-hard, and high-density memory applications, but the insufficient scalability of perovskite-based ferroelectric thin films and the high cost of conventional wide bandgap semiconductors are the most serious barriers for their practical applications. Here, we integrate highly scalable ferroelectric Hf _0.5 Zr _0.5 O ₂ (HZO) thin films on potentially low-cost bulk $\beta$ -Ga ₂ O ₃ substrates using an Al ₂ O ₃ buffer layer to form MFIS structures and investigate the microstructural and electrical properties of the HZO thin films and TaN/HZO/Al ₂ O ₃ / $\beta$ -Ga ₂ O ₃ (−201) MFIS structures. We find that the TaN/HZO/Al ₂ O ₃ / $\beta$ -Ga ₂ O ₃ (−201) MFIS structure annealed at 550 °C exhibits a memory effect, which is attributed to the ferroelectricity of the HZO thin film. This letter represents the critical first step in the implementation of $\beta$ -Ga ₂ O ₃ in HfO ₂ -based ferroelectric memories.