This paper presents a model for capacitance – voltage characteristics of bilayer metal-insulator-metal capacitors. The proposed model accounts for Space charge and Maxwell-Wagner polarization mechanisms. It is observed that the effective dielectric constant of stack is increased due to the accumulation of charges at the interface of high to low conductance materials due to the applied field. The proposed model for capacitance –
voltage characteristics shows a good agreement with experimental results by introducing carrier tunneling probability of dielectric stack. It is observed that the Maxwell Wagner polarization is dominant at low frequencies (<10 KHz). This model indicates that the nonlinearity can be suppressed by choosing the similar permittivity dielectric materials for fabrication of multilayer metal insulator metal capacitors.
