Series and parallel resistance effects on the C-V and G-V characteristics of Al/SiO2/Si structure

摘要

This paper investigates the electrical behavior of the C-V and G-V characteristics of Al/SiO2/Si structure. The modeling of capacitance and conductance has been developed from complex admittance treatment applied to the proposed equivalent circuit. Poisson transport equations have been used to determine the charge density, surface potential, total capacitance, and flatband and threshold voltages as a function of the gate voltage, frequency (omega), and series (R-s) and parallel (R-p) resistances. Results showed a frequency dispersion of C-V and G-V curves in both accumulation and inversion regimes. With increasing frequency, the accumulation capacitance is decreased, whereas the conductance is strongly increased. The shape, dispersion, and degradation of C-V and G-V characteristics are more influenced when parallel and series resistances (Rs, Rp) are dependent to substrate doping density. The variation of Rs and Rp values led to a reduction of flatband voltage from -1.40 to -1.26 V and increase of the threshold voltage negatively from -0.28 to -0.74 V. A good agreement has been observed between simulated and measured C-V and G-V curves obtained at high frequency.