Shih-Ching Chen

Bio: Shih-Ching Chen is an academic researcher from National Tsing Hua University. The author has contributed to research in topics: Threshold voltage & Thin-film transistor. The author has an hindex of 10, co-authored 24 publications receiving 923 citations.

Influence of electrode material on the resistive memory switching property of indium gallium zinc oxide thin films

Abstract: The InGaZnO taken as switching layer in resistive nonvolatile memory is proposed in this paper. The memory cells composed of Ti/InGaZnO/TiN reveal the bipolar switching behavior that keeps stable resistance ratio of 102 with switching responses over 100 cycles. The resistance switching is ascribed to the formation/disruption of conducting filaments upon electrochemical reaction near/at the bias-applied electrode. The influence of electrode material on resistance switching is investigated through Pt/InGaZnO/TiN devices, which perform the unipolar and bipolar behavior as applying bias on Pt and TiN electrode, respectively. Experimental results demonstrate that the switching behavior is selective by the electrode.

Behaviors of InGaZnO thin film transistor under illuminated positive gate-bias stress

Abstract: In this letter, we investigate the impact of the light illumination on the stability of indium–gallium– zinc oxide thin film transistors under positive gate-bias stress. The noticeable decrease in threshold voltage Vt shift more than 5.5 V under illuminated positive gate-bias stress indicates a superior reliability in contrast with the dark stress. The accelerated Vt recovery characteristic compared with dark recovery demonstrates that the charge detrapping effect was enhanced under illumination. Furthermore, the average effective energy barrier of charge trapping and detrapping was derived to verify that illumination can excite the trapped charges and accelerate the charge detrapping process. © 2010 American Institute of Physics. doi:10.1063/1.3481676

Influence of positive bias stress on N2O plasma improved InGaZnO thin film transistor

Abstract: A post-treatment using N2O-plasma is applied to enhance the electrical characteristics of amorphous indium gallium zinc oxide thin film transistors. Improvements in the field-effect mobility and the subthreshold swing demonstrate that interface states were passivated after N2O-plasma treatment, and a better stability under positive gate-bias stress was obtained in addition. The degradation of mobility, resulted from bias stress, reduces from 6.1% (untreated devices) to 2.6% (N2O-plasma treated devices). Nevertheless, a strange hump characteristic occurs in transfer curve during bias stress, inferring that a parasitic transistor had been caused by the gate-induced electrical field.

Bipolar Resistive Switching Characteristics of Transparent Indium Gallium Zinc Oxide Resistive Random Access Memory

Abstract: This study investigates a sputtered InGaZnO (IGZO) thin film to apply into a resistive random access memory device. After the formation of an indium tin oxide (ITO)/IGZO/ITO structure at room temperature, the device exhibits a repeatable bipolar resistance switching behavior without an electroforming process and an excellent transmittance in the visible region. The conduction mechanisms for low and high resistance states are dominated by Ohm's law and space-charge-limited current behavior, respectively. In retention and endurance tests, a resistance ratio of more than 1 order remains after 10 4 s at 90°C and after 100 dc voltage sweeping cycles.

Light-induced instability of an InGaZnO thin film transistor with and without SiOx passivation layer formed by plasma-enhanced-chemical-vapor-deposition

Abstract: This paper investigates the illuminated behaviors of InGaZnO thin film transistors with and without a SiOx passivation. For the passivated device, more interface states were generated during SiOx passivation layer deposition by plasma-enhanced-chemical-vapor-deposition. The enhanced trap-assisted photoexcited hole generation induces source side barrier lowering and causes an apparent subthreshold stretch-out phenomenon. However, for the unpassivated device, the fact that the threshold voltage shift in ambient oxygen is lower than in vacuum under light illumination suggests oxygen desorption and readsorption occurs simultaneously, which is consistent with the accelerated recovery rate in oxygen ambiance.

Enhanced performance of light-controlled conductive switching in hybrid cuprous oxide/reduced graphene oxide (Cu 2 O/rGO) nanocomposites

Abstract: A significant enhancement of photoresponse from the light-controlled conductive switching based on Cu2O/rGO nanocomposites was experimentally demonstrated. Cu2O/rGO nanocomposites were synthesized via a facile wet-reduced method. The crystalline structure, morphologies, and photoluminescence of the Cu2O/rGO nanocomposites were characterized and analyzed. The fabricated conductive switching was measured under the irradiation of a continuous laser. When the laser was turned on and off alternately, the photoconductive switching obviously displayed a state conversion between “on” and “off” reversibly. Furthermore, the typical current–voltage (I–V) and current–time (I–t) curves exhibited a relatively high switching ratio (Ion/Ioff) of 3.25 and a fast response time of 0.45 s. The excellent “on–off” characteristics of the device show promising applications in memory storage and logic circuits.

Recent Developments in p-Type Oxide Semiconductor Materials and Devices.

Abstract: The development of transparent p-type oxide semiconductors with good performance may be a true enabler for a variety of applications where transparency, power efficiency, and greater circuit complexity are needed. Such applications include transparent electronics, displays, sensors, photovoltaics, memristors, and electrochromics. Hence, here, recent developments in materials and devices based on p-type oxide semiconductors are reviewed, including ternary Cu-bearing oxides, binary copper oxides, tin monoxide, spinel oxides, and nickel oxides. The crystal and electronic structures of these materials are discussed, along with approaches to enhance valence-band dispersion to reduce effective mass and increase mobility. Strategies to reduce interfacial defects, off-state current, and material instability are suggested. Furthermore, it is shown that promising progress has been made in the performance of various types of devices based on p-type oxides. Several innovative approaches exist to fabricate transparent complementary metal oxide semiconductor (CMOS) devices, including novel device fabrication schemes and utilization of surface chemistry effects, resulting in good inverter gains. However, despite recent developments, p-type oxides still lag in performance behind their n-type counterparts, which have entered volume production in the display market. Recent successes along with the hurdles that stand in the way of commercial success of p-type oxide semiconductors are presented.