Work function effect of metal electrodes on the performance of amorphous Si–Zn–Sn–O thin-film transistors investigated by transmission line method

The electrical performance of amorphous Si–Zn–Sn–O (a-SZTO) thin-film transistors (TFTs) with various source/drain (S/D) electrodes materials was studied. Total resistance (R_T) and contact resistance (R_C) of a-SZTO TFT fabricated with different electrodes, such as Ag, Al, and Ti, were extracted using the transmission line method (TLM) method. Among the various source/drain metal electrodes, Ti S/D electrodes exhibited superior electrical characteristics and contact characteristics between the channel layer and S/D electrodes compared to other electrode materials, as Ti S/D electrodes form ohmic contacts between S/D electrodes and channel layer interfaces. The a-SZTO TFT with Ti S/D electrodes demonstrated improved electrical characteristics, including field-effect mobility (μ_FE) of 19.21 cm²/V s and subthreshold swing (S.S) of 0.64 V/decade.