Extending two-element capacitance extraction method toward ultraleaky gate oxides using a short-channel length

This letter demonstrates that the conventional two-element lumped model can provide valid capacitance-voltage (C-V ) characteristics for gate oxides with large tunneling current, if the gate length is reduced. The two-element models generally suffer from severe distortion of C-V due to tunneling current, resulting in poor oxide thickness extraction. The distortion can be suppressed using high frequencies in series model or using short gate lengths in parallel model. Considering instrument limits and manufacturability, however, the parallel model is more desirable. The distortion can be completely suppressed up to 10⁴ A/cm² of tunneling current, using gate lengths shorter than 0.2 μm in parallel model.