Effect of dielectric layer thickness on the electrical properties of mis devices / Ahmad Syauqi Mohd Nor

This research investigated the effect of dielectric thickness to the electrical properties metal-insulator-semiconductor (MIS) device. The MIS device were fabricated having PMMA:TiO2 and ZnO as dielectric and semiconductor layer, respectively. The PMMA:TiO2 nancomposite dielectric film were deposited at different deposition speed from 1000, 2000, 3000, 4000, 5000, and 6000 rpm. Results showed that there is difference in the nanocomposite dielectric film thickness when varying the deposition speed. As the spin speed increased, the thickness of the nanocomposite dielectric layer was reduced from 995.52 to 383.68 nm. For current-voltage (I-V) measurement, PMMA:TiO2 nanocomposite thin film showed an ohmic behavior meanwhile rectifying behavior for MIS devices. PMMA:TiO2 nanocomposite thin film give low current compared to MIS devices with current value approximately in range of 10-9 and 10-5 ampere respectively. As the PMMA:TiO2 nanocomposite thin film thickness decrease, the current increased from 2.155 x 10-9 to 2.906 x 10-9 ampere measured at 5V. The performance of MIS devices is degraded when thickness of the PMMA:TiO2 nanocomposite dielectric layer is decreased. The AFM image was observed to have an agglomeration of particles on the nanocomposite dielectric films. Roughness increased from 11.62 to 22.00 nm when spin speed are increased.