Performance Enhancement of InGaZnO Thin-Film Transistors via Rapid Cooling Process and Their Application in Logic Circuits

Nowadays, metal oxide thin-film transistors (TFTs) widely utilized in the driving circuits of various high-technology display products. Enhancing the electrical performance of metal oxide TFTs to meet the requirements of rapidly developing display products is a prominent research focus at present. In this article, we present a process of rapid cooling of annealed indium gallium zinc oxide (IGZO) TFTs using low-temperature deionized water for the first time. Compared to samples fabricated using conventional processes, the treated samples exhibited significantly enhanced electrical performance. The mobility has doubled (10.6 cm2V ${}^{-{1}}$ s ${}^{-{1}} \to {25.3}$ cm2V ${}^{-{1}}$ s ${}^{-{1}}$ ). The threshold voltage and subthreshold swing (S.S) were also very small (0.27 V, 0.25 V/dec). Drawing on semiconductor energy band theory, we developed a theoretical model to elucidate the evolution of defect states in IGZO during rapid cooling by integrating device electrical characterization and thin-film analysis of the active layer. The observed improvement in electrical performance was attributed to the rapid cooling process, which mitigated the formation of active layer defect states and reduced carrier trapping at trap energy levels. The enhanced devices were also applied to logic circuits, realizing the functions of inverters, NAND gates, and NOR gates. This work introduces a simple and environmentally friendly method, offering a novel strategy to enhance the performance of TFTs.