Sol–gel-processed Y2O3 films were used as an active-channel layer for RRAM devices. The effect of post-annealing temperature on structural, chemical, and electrical characteristics was investigated. The Y2O3-RRAM devices, comprising electrochemically active metal electrodes, Ag, and Indium tin oxide (ITO) electrodes exhibited the conventional bipolar RRAM device operation. The fabricated Ag/Y2O3/ITO RRAM devices, comprising 500-℃ annealed Y2O3 films, exhibited less oxygen vacancy and defect, which reduced the leakage current and boosted high-resistance state/low-resistance state ratio, more than 10^5, and promising nonvolatile memory properties without deterioration for 100 cycles and 10^4 seconds.

This study examines the effect of the annealing time of the Y 2 O 3 passivation layer on the electrical performances and bias stabilities of sol−geldeposited SnO 2 thin-film transistors (TFTs). The environmental stabilities of SnO 2 TFTs were examined. After optimizing the Y 2 O 3 passivation layers in SnO 2 TFTs, the field-effect mobility was 7.59 cm 2 /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 × 10 8 . V TH shifts were only −0.18 and +0.06 V under negative and positive bias stresses, respectively. The SnO 2 channel layer thickness and oxygenvacancy concentration in SnO 2 , which determine the carrier concentration, were successfully tuned by controlling the annealing time of the Y 2 O 3 passivation layers. An extremely thin Y 2 O 3 passivation layer effectively blocked external molecules, thus affecting the device performance. The electrical performance was maximized in SnO 2 TFTs using a 15 min-annealed Y 2 O 3 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.

Sol-gel processed SnO2 thin-film transistors (TFTs) were fabricated on SiO2/p+ Si substrates. The SnO2 active channel layer was deposited by the sol-gel spin coating method. Precursor concentration influenced the film thickness and surface roughness. As the concentration of the precursor was increased, the deposited films were thicker and smoother. The device performance was influenced by the thickness and roughness of the SnO2 active channel layer. Decreased precursor concentration resulted in a fabricated device with lower field-effect mobility, larger subthreshold swing (SS), and increased threshold voltage (Vth), originating from the lower free carrier concentration and increase in trap sites. The fabricated SnO2 TFTs, with an optimized 0.030 M precursor, had a field-effect mobility of 9.38 cm2/Vs, an SS of 1.99, an Ion/Ioff value of ~4.0 × 107, and showed enhancement mode operation and positive Vth, equal to 9.83 V.

In this study, sol–gel-processed amorphous-phase ZrO2 was used as an active channel material to improve the resistive switching properties of resistive random access memories (RRAMs). ITO/ZrO2/Ag RRAM devices exhibit the properties of bipolar RRAMs. The effect of the post-annealing temperature on the electrical properties of the ZrO2 RRAM was investigated. Unlike the ZrO2 films annealed at 400 and 500 °C, those annealed at 300 °C were in amorphous phase. The RRAM based on the amorphous-phase ZrO2 exhibited an improved high-resistance state (HRS) to low-resistance state ratio (over 106) as well as promising retention and endurance characteristics without deterioration. Furthermore, its disordered nature, which causes efficient carrier scattering, resulted in low carrier mobility and the lowest leakage current, influencing the HRS values.

Sol–gel-processed Y2O3 films were used as active channel layers for resistive random access memory (RRAM) devices. The fabricated ITO/Y2O3/Ag RRAM devices exhibited the properties of conventional bipolar memory devices. A triethylamine stabilizer with a high vapor pressure and low surface tension was added to realize the local electric field area. During drying and high-temperature post-annealing processes, the large convective flow enhanced the surface elevation, and the increased –OH groups accelerated the hydrolysis reaction and aggregation. These phenomena afforded Y2O3 films with an uneven surface morphology and an increased surface roughness. The increased roughness of the Y2O3 films attributable to the triethylamine stabilizer enhanced the local electrical field, improved device reliability, and achieved successful repetition of the switching properties over an extended period.