There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

Leu-M

An object is to provide a semiconductor device of which a manufacturing process is not complicated and by which cost can be suppressed, by forming a thin film transistor using an oxide semiconductor film typified by zinc oxide, and a manufacturing method thereof. For the semiconductor device, a gate electrode is formed over a substrate; a gate insulating film is formed covering the gate electrode; an oxide semiconductor film is formed over the gate insulating film; and a first conductive film and a second conductive film are formed over the oxide semiconductor film. The oxide semiconductor film has at least a crystallized region in a channel region.

Semiconductor device, and manufacturing method thereof

Zinc-ion batteries built on water-based electrolytes featuring compelling price-points, competitive performance, and enhanced safety represent advanced energy storage chemistry as a promising alternative to current lithium-ion battery systems. Attempts to develop rechargeable aqueous zinc-ion batteries (ZIBs) can be traced to as early as the 1980s; however, since 2015, the research activity in this field has surged throughout the world. Despite the achievements made in exploring electrode materials so far, significant challenges remain at the material level and even on the whole aqueous ZIBs system, leading to the failure of ZIBs to meet commercial requirements. This review aims to discuss how to pave the way for developing aqueous ZIBs. The current research efforts related to aqueous ZIBs electrode materials and electrolytes are summarized, including an analysis of the problems encountered in both cathode/anode materials and electrolyte optimization. Some concerns and feasible solutions for achieving practical aqueous ZIBs are discussed in detail. We would like to point out that merely improving the electrode materials is not enough; synergistic optimization strategies toward the whole battery system are also deeply needed. Finally, some perspectives are provided on the subsequent optimization design for further research efforts in the aqueous ZIB field.

Issues and opportunities facing aqueous zinc-ion batteries

Thin-film transistor (TFT) not only is the backbone of display technology, but also brings in fancy applications in the area of flexible electronics. TFT-based flexible circuit design however faces various challenges, such as unipolar devices and severe nonuniformity. In this paper, a sense amplifier based on dual-gate indium-gallium-zinc oxide (IGZO) TFTs is proposed for TFT-based static random access memory (SRAM) circuits. The pull-up transistors in the proposed sense amplifier are implemented with dual-gate TFTs while the pull-down transistors are implemented with conventional bottom-gate TFTs. By tuning the top gate of the pull-up transistors to achieve a negative threshold voltage as well as employing a specialized strength- adaptive pull-up structure, the proposed sense amplifier aims to reduce the offset voltage, sensing delay, and sensing power consumption simultaneously. Compared to the state-of-the-art IGZO-based sense amplifier, the proposed sense amplifier achieves up to 66.1% lower offset voltage, 68.9% shorter sensing delay, 72% dynamic power savings, and 66.3% leakage power savings.

A Pull-Up Adaptive Sense Amplifier Based on Dual-Gate IGZO TFTs

This paper proposes a low-voltage, segmented digital-to-analog converter (DAC) for active matrix organic light emitting diode (AMOLED) display. The reference voltage of each resistor string is reduced to a value within low-voltage range in this DAC so that low-voltage transistors can be adopted in the switch arrays and buffers to replace the middle-voltage transistors, leading to the saving of the DAC's area. This structure consists of piecewise linear resistors and a SC-voltage adder, which already exist in a peripheral compensation system of AMOLED. The simulation result of the proposed DAC shows that the DNL and INL are within ±0.5 LSB, and 64.28% of the switch area has been saved by adopting low-voltage transistors.

P-36: An Area-Efficient Segmented R-DAC Realized by Low-Voltage Transistors for AMOLED Driver Ics

Zinc oxide is a well-known wide band gap semiconductor material which can be applied to thin film transistors. Al-doped ZnO (AZO) has a better electrical conductivity than Zinc oxide at the same time with good photoelectric properties. In this paper, the method of atomic layer deposition (ALD) was used to prepare the ZnO and Al:ZnO (AZO) thin films as the active layers on silicon substrates at 100 °C. TEM and SEM were used to compare the characters of these films. While, transfer characteristic was an important basis for measuring the electrical characteristics of the devices with different active layers before and after annealing. The unannealed three-layers AZO-based thin film transistor (TFT) exhibits saturation mobility (µsat) of 5.97cm2V−1S−1, a lower subthreshold swing (SS) of 188mV/decade and a high Ion/Ioff ratio of 1.47 × 108.

Characteristic research of zinc oxide based thin film transistor by ALD technology

This paper aims at improving the performances of Titanium-doped Zinc-oxide (TZO) Thin-Film-Transistors (TFTs) by optimizing the source/drain materials. We successfully fabricate TZO TFTs with different source/drain materials, such as Al, Mo, Cr, Mo/Al/Mo and Cr/Al/Cr. No intentional substrate-heating is performed during each deposition step and the highest process temperature is 80°C. The results show that TFTs adopting Cr/Al/Cr as source/drain exhibit improved electrical properties with a high saturation mobility (μsat) of 171.4 cm2V−1S−1, a low subthreshold swing (SS) of 0.25 V/decade, a high I on /I off ratio of 2×108 and a threshold voltage (V th ) of 3.0V.

Titanium doped Zinc-oxide based Thin Film Transistors: Optimization of the source/drain materials

Back-channel-etch amorphous zinc tin oxide thin film transistors (a-ZTO TFTs) are fabricated with various thicknesses and deposition rates of gate insulator (GI). The devices exhibit a higher field-effect mobility and better electrical stress stability with GI thickness decreasing. Furthermore, field-effect mobility and electrical stress stability can be improved by slow GI deposition rate, caused by smoother GI surface. Moreover, combining with percolation theory, we propose a ZTO carrier transport model to explain the experimental phenomenon. The optimized device exhibits good electrical performances: modest saturation mobility of 10 cm2/Vs, on/off ratio > 108 and subthreshold swing of 0.60V/dec. Besides, V th shift under negative and positive V gs is −0.28V and +0.17V, respectively.

Shengdong Zhang

Papers

A Pull-Up Adaptive Sense Amplifier Based on Dual-Gate IGZO TFTs

P-36: An Area-Efficient Segmented R-DAC Realized by Low-Voltage Transistors for AMOLED Driver Ics

Characteristic research of zinc oxide based thin film transistor by ALD technology

Titanium doped Zinc-oxide based Thin Film Transistors: Optimization of the source/drain materials

Gate Insulator Influences on the Electrical Performance of Back-Channel-Etch Amorphous Zinc Tin Oxide (a-ZTO) Thin Film Transistors