A Separate Extraction Method for Asymmetric Source and Drain Resistances Using Frequency-Dispersive C-V Characteristics in Exfoliated MoS2 FET

Abstract

Asymmetric source and drain (S/D) series resistances (R-S and R-D) are unavoidable in exfoliated MoS2 field-effect transistors (EM-FETs). Through combining the capacitance-voltage (C-V) and current-voltage characteristics, the asymmetric R-S and R-D values are extracted separately. First, the frequency-dispersive C-V characteristics are analyzed in a frequency range of 0.3-10 kHz. Second, the intrinsic R-S and R-D values (R-S,R- int and R-D,R- int) are characterized through deembedding the parasitic pad capacitances (C-Pad = C-S,C- Pad + C-D,C- Pad) between the S/D metal and the bottom gate (G) in an overlapped region with the consideration of the structure-dependent parameters in the EM-FET. The proposed methodology is verified through comparison with the well-known channel resistance method, which is based on only the ID-VD characteristics in the linear region. Finally, R-S,R- int and R-D,R- int at various parasitic overlap areas are extracted separately with improved accuracy.