Electrical characterization of ZnO/4H-SiC n-p heterojunction diode

The structure and electrical properties of zinc oxide (ZnO) thin films fabricated by atomic layer deposition (ALD) as well as electrical properties of ZnO/4H‐SiC n–p heterojunction diodes were investigated. Hall measurements of ZnO films show their n‐type high intrinsic conductivity. Structural characterization of the ZnO layers performed using X‐ray diffraction show their polycrystalline morphology. Aluminum (Al) ohmic contacts fabricated to n‐ZnO demonstrate linear characteristics and low resistivities. The I–V measurements of ZnO/4H‐SiC n–p heterojunction showed strong diode‐like behavior with the low leakage current, turn‐on voltage of around 1.7 V, ideality factor of 1.17, and high rectification ratio. Extracting the built‐in potential (1.71 V) from the C–V measurements allowed to determine band offsets and thus the flat‐band energy diagram of produced heterostructure.