Extraction of Effective Mobility from nMOSFETs With Leaky Gate Dielectric Using Time Domain Reflectometry

Abstract

The effective mobility (µ eff ) of MOSFETs with ultrathin high-k gate dielectric (EOT = 0.85 nm) has been successfully extracted using a time domain reflectometry method. A ground-signal-ground-ground probe configuration is used to analyze the gate-to-channel capacitance (C gc ), gate-to-bulk capacitance (C gb ), and total gate capacitance (C g ) without a complex RF test structure. Using this method, the effective mobility can be extracted even in the presence of a high gate leakage current (∼30 A/cm 2 ) when the conventional split capacitance-voltage method using an impedance analyzer cannot be applied. IndexTerms-Effective mobility, MOSFET, split capacitance-voltage (C-V ), time domain reflectometry (TDR).