Extraction of Separated Source and Drain Resistances in Amorphous Indium-Gallium-Zinc Oxide TFTs Through C-V Characterization

Considering asymmetry caused by layout, process, and device degradation, separate extraction of the source and drain resistances, i.e., R-S and R-D, respectively, from the total resistance R-TOT is very important in the design, modeling, and characterization of amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistors (TFTs). Due to the insulated gate structure, however, separate extraction is difficult through direct-current I-V characterization. In this letter, we propose a simple and useful technique for separate extraction of R-S from R-D in a-IGZO TFTs through a two-terminal parallel-mode C-V technique. We experimentally verified the validity of the proposed technique by comparing the result with the source-to-drain resistance from the I-V characteristics.