Resistance random access memory

The creation of new organic-inorganic phototransistors with high and broad spectral photosensitivity is reported. The extended charge transport and photoconductivity between the layers in the bilayer structure results in a notable detectivity of over 10(12) Jones and a linear dynamic range of over 100 dB at a broad spectral bandwidth across the UV-NIR range. Furthermore, the considerably reduced persistent photocurrent effect of In-Ga-Zn-O (IGZO)-based hybrid phototransistors is first demonstrated via an organic-inorganic bilayer approach.

Ultrahigh and Broad Spectral Photodetectivity of an Organic–Inorganic Hybrid Phototransistor for Flexible Electronics

In this review, we provide an overview of our work in resistive switching mechanisms on oxide-based resistance random access memory (RRAM) devices. Based on the investigation of physical and chemical mechanisms, we focus on its materials, device structures, and treatment methods so as to provide an in-depth perspective of state-of-the-art oxide-based RRAM. The critical voltage and constant reaction energy properties were found, which can be used to prospectively modulate voltage and operation time to control RRAM device working performance and forecast material composition. The quantized switching phenomena in RRAM devices were demonstrated at ultra-cryogenic temperature (4K), which is attributed to the atomic-level reaction in metallic filament. In the aspect of chemical mechanisms, we use the Coulomb Faraday theorem to investigate the chemical reaction equations of RRAM for the first time. We can clearly observe that the first-order reaction series is the basis for chemical reaction during reset process in the study. Furthermore, the activation energy of chemical reactions can be extracted by changing temperature during the reset process, from which the oxygen ion reaction process can be found in the RRAM device. As for its materials, silicon oxide is compatible to semiconductor fabrication lines. It is especially promising for the silicon oxide-doped metal technology to be introduced into the industry. Based on that, double-ended graphene oxide-doped silicon oxide based via-structure RRAM with filament self-aligning formation, and self-current limiting operation ability is demonstrated. The outstanding device characteristics are attributed to the oxidation and reduction of graphene oxide flakes formed during the sputter process. Besides, we have also adopted a new concept of supercritical CO2 fluid treatment to efficiently reduce the operation current of RRAM devices for portable electronic applications.

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Physical and chemical mechanisms in oxide-based resistance random access memory.

Flexible transparent display is a promising candidate to visually communicate with each other in the future Internet of Things era. The flexible oxide thin-film transistors (TFTs) have attracted attention as a component for transparent display by its high performance and high transparency. The critical issue of flexible oxide TFTs for practical display applications, however, is the realization on transparent and flexible substrate without any damage and characteristic degradation. Here, the ultrathin, flexible, and transparent oxide TFTs for skin-like displays are demonstrated on an ultrathin flexible substrate using an inorganic-based laser liftoff process. In this way, skin-like ultrathin oxide TFTs are conformally attached onto various fabrics and human skin surface without any structural damage. Ultrathin flexible transparent oxide TFTs show high optical transparency of 83% and mobility of 40 cm2 V−1 s−1. The skin-like oxide TFTs show reliable performance under the electrical/optical stress tests and mechanical bending tests due to advanced device materials and systematic mechanical designs. Moreover, skin-like oxide logic inverter circuits composed of n-channel metal oxide semiconductor TFTs on ultrathin, transparent polyethylene terephthalate film have been realized.

Skin‐Like Oxide Thin‐Film Transistors for Transparent Displays

A review of studies using graphenes in energy conversion, energy storage and heat transfer development

This letter investigates the effect of repeated bending of flexible p-channel low-temperature polycrystalline–silicon thin-film transistors employing an ultra-low-temperature process (<673 K). Experimental results reveal that interface state density (Nit) and grain boundary trap density (Ntrap) after 10 000 width-axis tensile strain bending iterations are more pronounced than after equivalent width-axis compressive strain bending. Extracted interface and grain boundary traps both increase, which elevate trap assisted leakage. Furthermore, the bending distorts the Si–Si bonds in the polycrystalline silicon (Poly-Si) film, which causes more significant negative bias temperature instability (NBTI) degradation because strain-induced weak Si–Si bonds can react with dissociated H during NBTI stress.

Impact of repeated uniaxial mechanical strain on p-type flexible polycrystalline thin film transistors

This letter investigates the effect of gate/drain bias stress in InGaZnO thin-film transistors under light illumination and in a darkened environment. Drain current-gate voltage (ID-VG) as well as capacitance-voltage (C-V) transfer curves are measured to analyze the degradation behavior. The device characteristic exhibits a positively parallel shift after the gate/drain bias stress in the dark. On the other hand, the identical stress performed under light illumination leads to not only a negative shift but also a distortion of the C-V curve in the off state. Such phenomenon can be attributed to hole-trapping-induced barrier lowering near the drain side after illuminated bias stress.

Investigating the Drain-Bias-Induced Degradation Behavior Under Light Illumination for InGaZnO Thin-Film Transistors

Review of Present Reliability Challenges in Amorphous In-Ga-Zn-O Thin Film Transistors

This letter investigates degradation behaviors induced by the self-heating effect for amorphous indium-gallium-zinc-oxide (IGZO) (a-IGZO) thin-film transistors (TFTs) Both the surrounding oxide and other thermal insulating material and the low thermal conductivity of the IGZO layer itself cause the self-heating effect in a-IGZO TFTs The heated channel layer enhances threshold voltage shift, and the evolution of threshold voltage shift is found to be dominated by charge-trapping effect Further verifications indicate that the degree of threshold voltage shift is dependent on stress power only, and a wider channel leads to more severe self-heating effect

Ming-Yen Tsai

Papers

Impact of repeated uniaxial mechanical strain on p-type flexible polycrystalline thin film transistors

Investigating the Drain-Bias-Induced Degradation Behavior Under Light Illumination for InGaZnO Thin-Film Transistors

Review of Present Reliability Challenges in Amorphous In-Ga-Zn-O Thin Film Transistors

Self-Heating-Effect-Induced Degradation Behaviors in a-InGaZnO Thin-Film Transistors

Investigation of the gate-bias induced instability for InGaZnO TFTs under dark and light illumination