Improved Negative Bias Stress Stability of Sol–Gel-Processed Li-Doped SnO2 Thin-Film Transistors

Improved Environment Stability of Y2O3 RRAM Devices with Au Passivated Ag Top Electrodes

In this study, we fabricated sol-gel-processed Y2O3-based resistive random-access memory (RRAM) devices. The fabricated Y2O3 RRAM devices exhibited conventional bipolar RRAM device characteristics and did not require the forming process. The long-term stability of the RRAM devices was investigated. The Y2O3 RRAM devices with a 20 nm thick Ag top electrode showed an increase in the low resistance state (LRS) and high resistance state (HRS) and a decrease in the HRS/LRS ratio after 30 days owing to oxidation and corrosion of the Ag electrodes. However, Y2O3 RRAM devices with inert Au-passivated Ag electrodes showed a constant RRAM device performance after 30 days. The 150 nm-thick Au passivation layer successfully suppressed the oxidation and corrosion of the Ag electrode by minimizing the chance of contact between water or oxygen molecules and Ag electrodes. The Au/Ag/Y2O3/ITO RRAM devices exhibited more than 300 switching cycles with a decent resistive window (>103). They maintained constant LRS and HRS resistances for up to 104 s, without significant degradation of nonvolatile memory properties for 30 days while stored in air.

Water-Induced Nanometer-Thin Crystalline Indium-Praseodymium Oxide Channel Layers for Thin-Film Transistors

We report water-induced nanometer-thin crystalline indium praseodymium oxide (In-Pr-O) thin-film transistors (TFTs) for the first time. This aqueous route enables the formation of dense ultrathin (~6 nm) In-Pr-O thin films with near-atomic smoothness (~0.2 nm). The role of Pr doping is investigated by a battery of experimental techniques. It is revealed that as the Pr doping ratio increases from 0 to 10%, the oxygen vacancy-related defects could be greatly suppressed, leading to the improvement of TFT device characteristics and durability. The optimized In-Pr-O TFT demonstrates state-of-the-art electrical performance with mobility of 17.03 ± 1.19 cm²/Vs and on/off current ratio of ~10⁶ based on Si/SiO₂ substrate. This achievement is due to the low electronegativity and standard electrode potential of Pr, the high bond strength of Pr-O, same bixbyite structure of Pr₂O₃ and In₂O₃, and In-Pr-O channel's nanometer-thin and ultrasmooth nature. Therefore, the designed In-Pr-O channel holds great promise for next-generation transistors.

Applications of Thin Films in Microelectronics

Due to their versatility, thin films, which can be formed through many different approaches, are being used in various applications in microelectronics[...]

Environmentally and Electrically Stable Sol-Gel-Deposited SnO2 Thin-Film Transistors with Controlled Passivation Layer Diffusion Penetration Depth That Minimizes Mobility Degradation

This study examines the effect of the annealing time of the Y₂O₃ passivation layer on the electrical performances and bias stabilities of sol-gel-deposited SnO₂ thin-film transistors (TFTs). The environmental stabilities of SnO₂ TFTs were examined. After optimizing the Y₂O₃ passivation layers in SnO₂ TFTs, the field-effect mobility was 7.59 cm²/V•s, the V_TH was 9.16 V, the subthreshold swing (SS) was 0.88 V/decade, and the on/off-current ratio was approximately 1 × 10⁸. V_TH shifts were only -0.18 and +0.06 V under negative and positive bias stresses, respectively. The SnO₂ channel layer thickness and oxygen-vacancy concentration in SnO₂, which determine the carrier concentration, were successfully tuned by controlling the annealing time of the Y₂O₃ passivation layers. An extremely thin Y₂O₃ passivation layer effectively blocked external molecules, thus affecting the device performance. The electrical performance was maximized in SnO₂ TFTs using a 15 min-annealed Y₂O₃ passivation layer. In this TFT, the field-effect mobility was maximally retained and the bias and environmental stabilities were sustained over 90 days of air exposure.