Design and Fabrication of Vertical Metal/TiO2/β-Ga2O3 Dielectric Heterojunction Diode With Reverse Blocking Voltage of 1010 V

This work provides insight into the design principles and the reasonable construction of Ga
₂
O
₃
heterojunction diode. We chose TiO
₂
grown by atomic layer deposition (ALD) as a suitable insulator with a small conduction band offset of TiO<;span style="font-size: 14.5px;">
₂
/<;/span>
β
-Ga
₂
O
₃
heterojunction and a large dielectric constant. The type-I band alignment of the TiO
₂
/
β
-Ga
₂
O
₃
heterojunction was obtained using X-ray photoelectron spectroscopy (XPS). We demonstrated a high-performance vertical metal/TiO
₂
/
β
-Ga
₂
O
₃
dielectric heterojunction diode with reverse blocking voltage of 1010 V and differential ON-resistance of 3.3 mΩ·cm
²
. The proposed design principles of dielectric heterojunction diode and the insulator selection can also provide a simple, effective, and feasible technology for other wideband and ultrawideband semiconductors in which bipolar doping is challenging to achieve high power device performance.