Fabrication and Investigation of NiOx MSM Structure on 4H-SiC Substrate

Nickel oxide metal-semiconductor-metal structure was fabricated on 4H-SiC substrate by radio frequency magnetron sputtering from nickel oxide target and following electrode process. X-ray diffraction and scanning electron microscopy results indicate that the sputtered non-stoichiometric nickel oxide on silicon carbide is nanocrystalline. The current and voltage characteristic of the fabricated device was measured. When triggered by 365 nm incoming light, the current at 1 V and -1 V are 2.28 mA and -2.26 mA, respectively. Meanwhile, the dark current was as small as 26 $\mu$ A at both 1 V and -1 V. Furthermore, the secondary turn on behavior of the NiOx MSM structure was investigated. The results indicate that there are 3.35 eV barriers for electrons flowing from nickel electrodes to nickel oxide. Based on the investigated results, the equivalent circuit for secondary turn on behavior of the fabricated device was set up and simulated. The simulated curve matches the experimental curve well.