Effect of gate dielectric thicknesses on MOS photodiode performance and electrical properties

Different film thickness was used to investigate the effect of the Al2O3 as a dielectric material for the fabrication of Al/AL2O3/Si/Al MOS diode. Chemical spray pyrolysis method was employed in this work. A high rectification behavior was observed from current-voltage (I-V) measurements in forward and reverse in dark. Optimum ideality factor of (2.36) at 5 sprayed layers was observed, the breakdown voltage found to be 5 MV cm−1 while the barrier height was (0.65 eV) at the same layer thickness. Capacitance-voltage (C-V) measurements was carried out which ensure the formation of abrupt junction; the incorporating built-in potential (Vbi) was estimated and found to be (0.8 eV). In addition, the photodiode shows a good Responsivity of about (1.4, 1.8) Amp/watt at Uv and IR region respectively.