Electrical properties of Al/p-Si structure with Al2O3 thin film fabricated by atomic layer deposition system

Abstract

Al2O3 insulator layer was deposited by atomic layer deposition (ALD) technique on p-type Si ⟨111⟩ and the Al/Al2O3/p-Si metal/insulator/semiconductor (MIS) structures were fabricated. The current–voltage (I−V) characteristics of these structures were investigated in two different temperatures. The main electrical parameters such as the ideality factor (n), zero bias barrier height (ΦBo(I−V)), and series resistance (Rs) values were found for 300 and 400K. The energy density distribution profiles of the interface state density (Nss) were determined from the I−V characteristics. In addition, the capacitance–voltage (C−V) and conductance–voltage (G/w−V) characteristics of devices were investigated in the frequency range 50–1000kHz at room temperature. Frequency-dependent electrical characteristics such as doping acceptor concentration (NA), energy difference between the valance band edge and bulk Fermi level (EF), diffusion potential (VD), barrier height (ΦB(C−V)), the image force barrier lowering (ΔΦB), maximum electric field (Em), and Rs values were determined using C−V and G/w−V plots. In addition, the Nss values were performed using Hill–Coleman method. According to experimental results, the locations of Nss and Rs have an important effect on I−V, C−V and G/w−V plots of MIS structure.