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

Asymmetric source and drain (S/D) series resistances (
$R_{S}$
and
$R_{D}$
) are unavoidable in exfoliated MoS
₂
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 (
$R_{S,int}$
and
$R_{D,int})$
are characterized through deembedding the parasitic pad capacitances (
$C_{Pad} = C_{S,Pad}+C_{D,Pad})$
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
$I_{D}$
–
$V_{D}$
characteristics in the linear region. Finally,
$R_{S,int}$
and
$R_{D,int}$
at various parasitic overlap areas are extracted separately with improved accuracy.