Dual-Sweep Combinational Transconductance Technique for Separate Extraction of Parasitic Resistances in Amorphous Thin-Film Transistors

We report a dual-sweep combinational transconductance technique for separate extraction of parasitic source ( ${R}_{S}$ ) and drain ( $R_{D}$ ) resistances in thin-film transistors (TFTs) by combining forward and reverse transfer characteristics. In the proposed technique, gate bias-dependent total resistance [ $R_{\rm TOT}$ ( $V_{\rm GS}$ )] and degradation of the transcond- uctance due to the parasitic resistance at the source terminal during the dual-sweep characterization are employed. Applying the proposed technique to amorphous oxide semiconductor TFTs with various combinations of channel length ( ${L}$ ) and width ( $W$ ), we successfully separated $R_{S}$ and $R_{D}$ . A model for the $W$ - and $L$ -dependences of the extracted parasitic resistances is also provided.