Integration and Electrical Properties of Ferroelectric Hf0.5Zr0.5O2 Thin Film on Bulk $\beta$ -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.