Influence of Annealing Atmosphere on the Characteristics of Ga(2)O(3)/4H-SiC n-n Heterojunction Diodes

Ga(2)O(3)/4H-SiC n-n isotype heterojunction diodes were fabricated by depositing Ga(2)O(3) thin films by RF magnetron sputtering. The influence of annealing atmosphere on the film quality and electrical properties of Ga(2)O(3) layers was investigated. X-ray diffraction (XRD) analysis showed a significant increase in the peak intensities of different faces of β-Ga(2)O(3) {(−201), (−401) and (002)}. X-ray photoelectron spectroscopy (XPS) measurement showed that the atomic ratio of oxygen increases under high-temperature annealing. Moreover, an N(2)-annealed diode exhibited a greater rectifying ratio and a lower thermal activation energy owing to the decrease in oxygen-related traps and vacancies on the Ga(2)O(3) film and Ga(2)O(3)–metal interface.