Fabrication and electrical characterization of solution processed Ni/MgO/p-Si/Al MIS diodes

This study reports on the fabrication and characterization of Ni/MgO/p-Si/Al MIS diodes to investigate the electrical and dielectric properties of the fabricated structures. The MgO thin films were deposited on p-type silicon with (100) orientation using solution processed method that includes combined sol–gel and spin coating techniques. The structural analysis performed using X-ray diffractometry reveals polycrystalline nature of the deposited MgO films having crystallite size of 30 nm and dislocation density 1.077 × 1015 lines/m2. The fabricated MIS structure exhibits good rectification behavior over the measured bias range which was also analyzed using various well-accepted conduction mechanisms viz. Poole–Frenkel emission, Schottky emission, Fowler‒Nordheim tunneling and Space charge limited conduction. Further, from the C–V characteristics analysis, the barrier heights obtained for Ni/MgO/p-Si/Al structures are 1.26 eV, 1.24 eV, 1.21 eV and 1.11 eV at frequencies 10 kHz, 100 kHz, 300 kHz and 1 MHz. Moreover, the impedance spectrum of the Ni/MgO/p-Si/Al MIS diodes was also analyzed using equivalent circuit showing significant change in the internal resistance and capacitance of the diode.