Effect of frequency and bias voltage on the electrical and dielectric properties of atomic layer deposited Al/Al2O3/ p-Si MOS structure at room temperature

Abstract

In the present work , the effect of frequency and bias voltage on electrical and dielectric properties of Al/Al₂O₃/p-Si structure in which Al₂O₃ dielectric layer is deposited by ALD using TMA and water as precursors, has been studied. The parameters were extracted from C-V and G-V characteristics by varying frequency from 50kHz to 1MHz at room temperature. Experimental results show that dielectric constant (ε'), dielectric loss (ε'') and dielectric loss tangent (tan δ) decrease with increasing frequency, while ac conductivity (σ_ac) increases with increasing frequency. It is also observed that interface states density, series resistance and thickness of dielectric layer are major parameters which influence electrical and dielectric properties of MOS structure. The present results indicate that ALD films have low interface states density values and show superior properties than samples prepared by other techniques and are promising for future applications.