Effect of NiOx Field Ring Deposition Condition on Characteristics of Ga2O3 Schottky Diodes

In this paper, we fabricated a series of β-Ga
2
O
3
Schottky diodes with p-type NiO
x
field rings. The effect of NiO
x
sputtering gas atmosphere with different O
2
/Ar flux ratios upon the characteristics of β-Ga
2
O
3
Schottky diodes is investigated in depth and the physical mechanism is analyzed. The electrical characteristics of the β-Ga
2
O
3
Schottky diodes with p-type NiO
x
field rings are studied systematically. All β-Ga
2
O
3
Schottky diodes with NiO
x
field rings obtained by deposition under an oxygen atmosphere show great advantages in terms of device inverse performance parameters, such as a significant increase in the breakdown voltage of the device. In particular, β-Ga
2
O
3
Schottky diodes with p-type NiO
x
field rings deposited at an O
2
/Ar flux ratio of 30% exhibit a low specific on-resistance of 1.73 mΩ•cm
²
and a high breakdown voltage of 1.85 kV, resulting in a high power figure-of-merit (PFOM) of 1.98 GW/cm
²
.