NiO thin films by MOCVD of Ni(dmamb)2 and their resistance switching phenomena

We have synthesized the volatile, liquid, nickel precursor Ni(dmamb)2, nickel bis(1-dimethylamino-2-methyl-2-butanolate), Ni[OC(CH3)(C2H5)CH2N(CH3)2]2, and employed it in the MOCVD of nickel oxide (NiO). A stainless steel, cold-wall, low-pressure reactor was employed to grow the NiO films on Si and Pt/SiO2/Si substrates. In addition, the resistance switching property of the Pt/NiO/Pt capacitor structure was investigated. The substrate temperature was varied in the range 230–410 °C. The films deposited were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and I–V measurements. They were polycrystalline showing dominantly the NiO(111) peak in their X-ray diffraction patterns. The films were found to be almost stoichiometric with the Ni:O ratio of 1.1:0.9 and no appreciable amount of carbon incorporation was detected by XPS. The I–V measurements revealed an interesting switching property of the NiO films showing low and high resistance states thereby suggesting their application as ReRAM devices.