علی بهاری

Some issues, such as leakage and tunneling currents, and light atom penetration through a thin gate dielectric, are threatening for silicon dioxide to be used as a suitable gate dielectric material for the next-generation metal-insulator-semiconductor-field-effect-transistor (MISFET) devices. A novel gate dielectric material for MISFET has been synthesized via the Pechini method by combining graphene oxide (GO)/dicalcium silicate (C2S) components. First, GO nanoparticles were synthesized via the Hummer method and C2S—via the Pechini method and then 0.1, 0.2, 0.4 and 0.8 the weight percentages (wt %) of GO were added into the C2S matrix. Their nanostructural properties were studied by the field emission scanning electron microscopy X-ray diffraction, Fourier transform infrared, thermo-gravimetry and differential scanning calorimetry. The electrical properties of GO/C2S nanocomposites, metal (Al)-GO/C2S insulator-Si (semiconductor) were fabricated by the physical vapor deposition technique at 10–7 Torr. The capacity, current-voltage relationship, quality factor, dissipation factor were measured with an LCR meter GPS-132A and 4-probe techniques. The frequency response of dielectric properties, dielectric constant, dielectric loss, and AC electrical conductivity, of the examined samples were studied. The electrical measurements showed that a sample with 0.4 wt % of GO nanoparticles has a higher dielectric constant at a frequency of 120 kHz (K = 62) and 1 kHz (K = 30), a lower leakage current (20 × 10–6 A/cm2), a good carrier mobility (7.62 cm2/V s), a low threshold voltage (2.9 V), a large current ION/IOFF ratio (1.25 × 103), and a higher quality factor (32.4). Therefore, C2S/GO nanocomposite with 0.4 wt % Go nanoparticles can be introduced as an alternative gate dielectric material for the next generation of MISFET devices.