InZnSnO-Based Electronic Devices for Flat Panel Display Applications

Abstract

This work demonstrates the versatility of amorphous InZnSnO (a-IZTO) oxide semiconductor, covering from the thin film transistor (TFT) to the resistive random access memory (RRAM) technologies for system-on-panel applications. The high-performance a-IZTO TFTs with effective carry mobility of 39.6 cm 2 /V s, threshold voltage of −0.28 V and subthreshold swing of 0.25 decade/V are obtained in this study. Thermal post-annealing also was used to provide stable electrical characteristics with a few threshold voltage shift after positive gate bias stress. On the other hand, the RRAM device with a-IZTO film acting as active layer exhibits superior bipolar resistive switching characteristics. The wide (>10) resistance window and the stability endurance of hundreds cycle are achieved. Both of the proposed a-IZTO TFT and RRAM have promising potential to be integrated with a-IZTO-based periphery electronic circuits for flat-panel display applications. The system-on-panel (SoP) concept has been proposed to enable various functional devices, such as driver, sensor, memory and controller devices, to be integrated on a single panel for achieving highperformance, low-cost and more compact display products.1,2 For the technology integration, several key electric devices, such as thin film transistor (TFT) and nonvolatile memory, are preferred to be fabricated with the same material and similar processes for manufacture with ease. In the SoP architecture, TFT devices are not only used to control the transmittance of the pixel, but also have to construct all the system circuits around the panel as basic switch or driver devices. In order to reduce the power consumption and scale down the bezel widths, the performance requirements of the TFT become critical especially on the mobility. Amorphous silicon, the most widely used material in TFTs as the channel layer, is suffering from the low mobility and leakage current. In 2004, the most popular material, amorphous indium gallium zinc oxide (a-IGZO), was proposed by H. Hosono et al. and attracted a lot of attention as a backplane material according to its transparency, high mobility and better bias stability.3,4 However, the average mobility of a-IGZO TFTs is around 20 cm 2 /V s and it's not enough to drive the circuits surrounded the display panel. 5,6 Besides, the high wet etching rate of a-IGZO, during the formation process of Mo or Al source (S)/drain (D) electrodes in PAN solution, causes the difficulty for fabricating a-IGZO TFTs with back-channel-etch (BCE) structure which is cheaper and simpler process than the etching stop one. 7-9The technology of memory device embedded in a display pixel can reduce power consumption and provide various functions for system driving circuits. The most popular nonvolatile memory, flash memory, has been widely used in many electronic products such as universal serial bus (USB), program-able logic circuit and radio-frequency identification (RFID).10 However, the technology barrier for the integration of flash device on glass substrate is high si...

Compositional Engineering of Hf‐Doped InZnSnO Films for High‐Performance and Stability Amorphous Oxide Semiconductor Thin Film Transistors

“…As discussed by Liu et al and He et al, even at 400 °C, the sputtered InZnSnO films retained their amorphous structure, while below 500 °C, the sputtered HfO 2 films maintained amorphous structure. [72,73] Figure 3c shows that the surface field emission-scanning electron microscopy (FE-SEM) images of the Hf:InZnSnO films revealed flat and smooth surface morphology, which is characteristic of amorphous structure, even at different sputtering power. There is no evident change in the surface of films without regard to the change of chemical composition.…”

Glucose-based resistive random access memory for transient electronics

“…with a display panel, is a well-known technology that has been extensively studied in the display field. Especially, the non-volatile memory devices embedded in the pixels of display panels can dramatically reduce the power consumption and enable a variety of functions as there is no need to operate a column line with a large load capacitance [10][11][12]. Therefore, resistive random access memory (RRAM) is one of the most interesting non-volatile memory candidates for integration in the display panel, due to its simple device structure (metal-insulator-metal), fast switching speed, and high scalability.…”

Development of resistive random access memory for next-generation embedded non-volatile memory application

“…For large-area electronics (LAE) application, indium-gallium-zinc-oxide (IGZO) thin film transistor (TFT) has drawn much attention owing to its low cost, high field-effect mobility, good uniformity for large area deposition, and low process temperature [163][164][165]. In addition, the nonvolatile memory is another key element that can be embedded in the LAE circuits for power reduction [166]. Resistive random access memory (RRAM) can be easily integrated with TFT to form the one-transistor-one-resistor (1T1R) architecture due to its non-volatility, simple structure, low operation voltage, and low process temperature [8].…”