In this study, molybdenum tungsten/amorphous InGaZnO (a-IGZO)/TiO₂/n-type Si-based resistive random access memory (ReRAM) is manufactured. After deposition of the a-IGZO, annealing was performed at 200, 300, 400, and 500 °C for approximately 1 h in order to analyze the effect of temperature change on the ReRAM after post annealing in a furnace. As a result of measuring the current-voltage curve, the a-IGZO/TiO₂-based ReRAM annealed at 400 °C reached compliance current in a low-resistance state, and showed the most complete hysteresis curve. In the a-IGZO layer annealed at 400 °C, the O₁/O_total value increased most significantly, to approximately 78.2%, and the O₃/O_total value decreased the most, to approximately 2.6%. As a result, the a-IGZO/TiO₂-based ReRAM annealed at 400 °C reduced conductivity and prevented an increase in leakage current caused by oxygen vacancies with sufficient recovery of the metal-oxygen bond. Scanning electron microscopy analysis revealed that the a-IGZO surface showed hillocks at a high post annealing temperature of 500 °C, which greatly increased the surface roughness and caused the surface area performance to deteriorate. Finally, as a result of measuring the capacitance-voltage curve in the a-IGZO/TiO₂-based ReRAM in the range of −2 V to 4 V, the accumulation capacitance value of the ReRAM annealed at 400 °C increased most in a nonvolatile behavior.

In this study, the effects of femtosecond laser postannealingwere experimentally confirmed by applying it to amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistor (TFT) with enhanced electrical characteristics. We confirmed that a-IGZO TFTs fabricated by applying femtosecond laser annealing for 50 and 100 s improved more than as-deposited a-IGZO TFTs before annealing. However, a-IGZOTFTs irradiated formore than 150 s degraded in overall performance compared with the as-deposited a-IGZO TFTs. The result of the X-ray photoelectron spectroscopy measurement of the O1s peak on the a-IGZO thin-film indicated that the O ₁ /O _total value dropped to approximately 44.3%, and the O ₃ /O _total value increased to approximately 17.6% when the a-IGZO thin film was irradiated for 150 s. As a result, oxygen vacancies remained without sufficient recovery of the metal-oxygen bond, and as the electron concentration increased, the conductivity increased, and the performance of the TFT decreased due to an increase in leakage current. A resistive load inverter was fabricated by connectinga TFT irradiatedwith the femtosecond laser at the best-performing time of approximately 100 s. The result of measuring the reversal characteristics confirmed a large inversion at the rising and falling edges.

Amorphous indium–gallium–zinc oxide (a-IGZO) is a widely studied semiconductor for cutting-edge electronics applications because of its low absorbance, high charge carrier mobility, and versatility. For the practical application of a-IGZO thin films, postdeposition thermal treatment is typically applied to enhance the device’s performance. Here, we present a study on the effect of oxygen plasma posttreatment of thermally annealed, sputter-deposited a-IGZO thin films to determine the optimal treatment time using a helical plasma source. The performance of devices with a-IGZO active layers exposed to oxygen plasma for different durations is compared, and the stability under constant bias is evaluated. It is found that temporarily exposing the film surface to high-energy oxygen species can improve the charge transport properties, resulting in superior device performance such as more than tenfold increase in the ON–OFF ratio, a nearly doubling of charge carrier mobility and improved bias stress stability. However, under prolonged exposure, the device deteriorates, indicating the importance of properly designing and optimizing the fabrication processes of oxide semiconductor devices. To demonstrate the practical applicability of the transistors with optimized a-IGZO active layers, load-type inverters are prepared, and their performance is evaluated and compared quantitatively to that of a device with a pristine a-IGZO active layer.

Solution-processed In-Zn oxide (IZO) semiconductor thin-film transistors (TFTs) were fabricated with passivation layers of either poly(methyl methacrylate) (PMMA) or cyclic transparent optical polymer (CYTOP). According to the transfer curves obtained on the day of fabrication and after 200 days, the drain-source current of the IZO TFT without a passivation layer decreased by approximately 37 %. For the PMMA-passivated IZO TFT, it decreased by approximately 31 %. The current for the CYTOPpassivated IZO TFT showed significantly lower, only 7 % deterioration. Hence, the CYTOP-passivated IZO TFT exhibited improved electrical stability under long term ambient storage. This was attributed to the difference in the chemical composition of the two polymers, as CYTOP is a fluoropolymer, while PMMA is an ester group containing organic polymer. We show, passivation of the active layer with the proper organic film improves the stability of the high-performance solution-processed IZO TFTs.

The low-temperature annealing process has a critical impact on the electrical performance of thin-film transistors (TFTs). This paper reports significant performance enhancements of TFTs using a femtosecond laser pre-annealing (FLA)-based preparation method. The solution-processed In ₂ O ₃ films were fabricated by FLA at various laser irradiation times and then annealed on a hot-plate at 230 °C. When the FLA time was set to 30 s, the device exhibited high saturation mobility of 10.03 ± 0.64 cm ² /Vs, I _on /I _off of 3.4×10 ⁵ , low V _TH of 0.14 ± 0.64 V, and small SS of 1.44 ± 0.37 V/dec. The FLA process improved the formation of M-O lattices effectively, which led to an improvement in mobility. Furthermore, the gate-bias-stress stability and time-dependent environmental stability were improved considerably by the FLA process. These results show that high-performance In ₂ O ₃ TFTs can be prepared at low temperatures using FLA-centered annealing technology. This work suggests that the FLA preparation method has tremendous potential for the fabrication of low-cost, high performance, and flexible TFT devices.