Effect of Oxygen Annealing on the Characteristics of Isotype Ga2O3/4H-SiC Heterojunction Diodes

Abstract

Ga2O3/n-type 4H-SiC heterojunction diodes were fabricated by depositing Ga2O3 thin films on off-axis cut n type 4H-SiC substrates by RF magnetron sputtering. The influence of oxygen atmosphere annealing on the film quality and optical properties of Ga2O3 layers is investigated. The I–V characteristics of the diodes are acquired in the range from 25 to 175 °C with temperature step of 50 °C. The annealed diodes exhibit improved rectifying ratio (∼1 × 108 for ±2V) and an improved ideality factor (1.83) at 25 °C. Additionally, the photodiode that was annealed in the presence of an oxygen atmosphere shows an increased photocurrent, higher responsivity and an improved time dependent photo-response than as-grown devices.