Fabrication and characterization of ZnFe 2O4 thin film based metal- insulator-semiconductor capacitors

Thin films of zinc ferrite (ZnFe 2O4) were deposited on glass, quartz and p-silicon (100) substrates by the sol-gel method. The structural properties of the films were studied using x-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The XRD data show the film having a spinel structure and the crystalline phase exists after annealing at 500 o C for 2 h in air. The SEM and AFM images show the nano-crystalline nature of the films. The optical transmittance decreased with increase of annealing temperature. The optical band gap energy was estimated at different annealing temperatures and found to be 2.71 eV after annealing at 400 o C. The metal-insulator-semiconductor (MIS) capacitors were fabricated using ZnFe 2O4 films on p-silicon (100) substrates. The capacitance-voltage (C-V), dissipation-voltage (D-V) and currentvoltage (I-V) characteristics were studied. The dependence of dielectric constant on annealing temperature and signal frequency was analyzed. The variation of current density and resistivity of the ZnFe 2O4 films with annealing temperature was also explored.