Circuits implemented with high-performance amorphous-indium-gallium-zinc-oxide thin-film transistors (TFTs) are realized on polyimide/polyethylene-terephthalate plastic substrates. The TFTs exhibit a saturation mobility of 19 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> /V·s and gate voltage swing ~0.14 V/dec. For an input 20 V, 11-stage ring oscillator operates at 94.8 kHz propagation delay time 0.48 μs. A shift register,...

We present here an amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistor (TFT) in which the accumulation layer is not only confined to a-IGZO/gate-insulator interface, but extends entire depth of a-IGZO. This bulk TFT achieved by use top- and bottom-gate, that are electrically tied together, resulting drain current over seven times higher than a single-gate device, for a-IGZO thickness 10 nm. Thus, high drive relatively small channel width due accumulation. Furthermore, being...

Major obstacles toward the manufacture of transparent and flexible display screens include difficulty finding semiconductors electrodes, temperature restrictions plastic substrates, bulging or warping electronics during processing. Here we report fabrication performance fully rollable thin-film transistor (TFT) circuits for applications. The TFTs employ an amorphous indium–gallium–zinc oxide semiconductor (with optical band gap 3.1 eV) indium–zinc conductive are built on 15-μm-thick...

Abstract Advancements in thin-film transistor (TFT) technology have extended to electronics that can withstand extreme bending or even folding. Although the use of ultrathin plastic substrates has achieved considerable advancement towards this end, free-standing plastics inevitably suffer from mechanical instability and are very difficult handle during TFT fabrication. Here, addition a 1.5 μm-thick polyimide (PI) substrate, PI film is also deposited on top devices ensure located at neutral...

Abstract Radiating amorphous In–Ga–Zn–O (a-IGZO) thin-film transistors (TFTs) with deep ultraviolet light (λ = 175 nm) is found to induce rigid negative threshold-voltage shift, as well a subthreshold hump and an increase in subthreshold-voltage slope. These changes are attributed the photo creation ionization of oxygen vacancy states (V O ), which confined mainly top surface a-IGZO film (backchannel). Photoionization these generates free electrons transition from neutral ionized V...

A high-performance inverter implemented with single-gated driving and dual-gated load amorphous-indium–gallium–zinc–oxide thin-film transistors (TFTs) is demonstrated. The threshold voltage of the TFT shifts to negative gate direction when a constant positive bias applied on top while sweeping bottom gate. Using bias, can be operated in depletion mode realize inverters excellent switching characteristics, such as wider swing range higher noise margin.

A damage-free back channel wet etch process is developed for inverted staggered amorphous-InGaZn04 (a-IGZO) thin-film transistors (TFTs). The key ingredient a less acidic etchant such as hydrogen peroxide (H2O2)-based etchants rather than the commonly used nitric acid (HNO3)-based etch. Scanning electron microscope images and X-ray photoelectron spectroscopy (XPS) data are to monitor damage on a-IGZO profiles of source drain electrodes. Better profile fewer residues along with superior TFT...

Owing to bulk-accumulation, dual-gate (DG) amorphous-indium-gallium-zinc-oxide (a-IGZO) thin-film transistors (TFTs) with top- and bottom-gates electrically tied together (DG-driving) exhibit 2.53 times higher ON-current subthreshold voltage swing of ~ 180 mV/decade, which is 50% lower than that single-gate (SG)-driven a-IGZO TFTs. Here, through simulation experimental results, we demonstrate the use DG-driven back-channel-etched TFTs a top-gate offset structure enhances switching speed...

A hump in the subthreshold regime of transfer characteristics is reported for amorphous-indium-galium-zinc-oxide thin-film transistors (TFTs) when they are exposed to large positive gate bias-stress. As stress time progresses, shift two opposite directions; main transistor shifts positive, while negative gate-voltage direction. The occurs at same current level all TFTs with channel widths ranging from 10 200 μm, which supports exclusion bulk and back surface effects. We therefore propose...

We have analyzed the effect of applying positive bias stress (PBS) to amorphous-indium-gallium-zinc-oxide (a-IGZO) thin-film transistors (TFTs) immediately after negative under illumination (NBIS). By monitoring TFT current-voltage and capacitance-voltage characteristics, we found that PBS facilitates recovery process. NBIS results in charge trapping at active-layer/gate-insulator interface formation shallow donors bulk a-IGZO when neutral oxygen vacancies are ionized by hole capture. In...

The evolution with time of interface trap density and bulk states in amorphous-indium-gallium-zinc-oxide thin-film transistors (TFTs), for negative-bias-under-illumination-stress (NBIS), is traced. Based on the combined analysis TFT current-voltage capacitance-voltage characteristics, position Fermi energy, flat band voltage, density, gap state per unit energy are investigated as function NBIS applied gate voltage. These key parameters help to identify degradation phenomena responsible...

We studied the environmental stability of amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistors (TFTs) with single-layer (SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) and bilayer /SiN xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> passivation under high-humidity (80%) storage. During 30 days investigation, all passivated TFTs showed negative turn-ON voltage shifts (AVON), size which increased storing time. The A...

We report thermally stable coplanar amorphous-indium-gallium-zinc-oxide (a-IGZO) thin-film transistors (TFTs) with heavily doped n+ a-IGZO source/drain regions. Doping is through He plasma treatment in which the resistivity of decreases from 2.98 Ω cm to 2.79 × 10−3 after treatment, and then it increases 7.92 10−2 annealing at 300 °C. From analysis X-ray photoelectron spectroscopy, concentration oxygen vacancies treated n+a-IGZO does not change much thermal °C, indicating a-IGZO, even for...

We propose a way to achieve high-speed circuits with dual-gate (DG) bulk-accumulation back-channeletched (BCE) amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistors (TFTs) using the pseudo-CMOS structure. The DG BCE a-IGZO TFTs exhibit field-effect mobility (μ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">FE</sub> ), threshold voltage (Vth), and subthreshold swing of 30 ± 3 cm <sup...

Advancement in thin‐film transistor (TFT) technologies has extended to applications that can withstand extreme bending or folding. The changes of the performances amorphous‐indium‐gallium‐zinc‐oxide (a‐IGZO) TFTs on polyimide substrate after application mechanical strain are studied. TFT designs include mesh and strip patterned source/drain metal lines as well a‐IGZO semiconductor layer. robustness with 2.17% corresponding radius 0.32 mm is tested no crack generation even 60 000 cycles...

We report the numerical simulation of effect a dual gate (DG) TFT structure operating under driving on improving negative bias illumination stress (NBIS) amorphous indium gallium zinc oxide thin-film transistors (a-IGZO TFTs). With respect to transfer characteristics a-IGZO TFTs, we show larger threshold voltage shift (ΔVTH) with increasing active layer thickness. This trend is confirmed by TCAD simulation, where initial curve plotted varying thickness keeping constant density states. Under...

A threshold voltage (Vth) dependence on channel length (L) is reported for amorphous-indium-gallium-zinc-oxide thin-film transistors (TFTs). Vth found to shift negatively with decreasing L and the negative drastic in TFTs &amp;lt; 4 μm. Combined analysis of current-voltage (I-V) capacitance-voltage (C-V) curves shows that Fermi energy (EF) at flat band shifts towards conduction (EC) L, hence shift. Using same analysis, carrier density (nFB) also increase revealing unintentional doping by...

Amorphous-InGaZnO4 (a-IGZO) thin-film transistors (TFTs) on glass undergo large positive threshold voltage shifts (ΔVTH) under high current stress (HCS)—a consequence of Joule heating the active-layer. Here, we show that when active layer is split into smaller parts, HCS induces negligible ΔVTH. When heats up during HCS, conducting electrons in channel gain enough energy to surmount barrier at active-layer/gate-insulator interface and become trapped deep states inside gate-insulator....

Stability under negative-bias-illumination-stress (NBIS) of dual-gate (top- and bottom-gate) amorphous-indium-gallium-zinc-oxide (a-IGZO) thin-film transistors is investigated. It found that the negative threshold-voltage shift (ΔV <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TH</sub> ) induced by NBIS much smaller driving (when two gates are electrically tied together) compared with single-gate driving. For a 20 nm-thick a-IGZO active layer,...

We report a high-speed and low-voltage-driven shift register utilizing self-aligned coplanar amorphous-indium-gallium-zinc-oxide thin-film transistors (a -IGZO TFTs). The a-IGZO TFTs exhibit field-effect mobility, threshold voltage, gate-voltage swing of 24.7 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> /V·s, 0.2 V, 118 mV/dec, respectively. rise fall times the at supply voltage ( <i xmlns:xlink="http://www.w3.org/1999/xlink">V</i>...

We report the design and fabrication of a high-yield, high-speed, an ultranarrow gate driver with amorphous-indium - gallium zinc-oxide thin-film transistors (TFTs). A single stage consists nine TFTs one capacitor. For supply voltage (VDD) 20 V, operates pulsewidth 2 μs, which is compatible 4k2k display operated at 240 Hz. In addition, proposed ultrasmall in physical size, only 30 μm width (pitch) 720 length, thus suitable for small-size, high-resolution, narrow bezel display.

A highly stable, dual-gate (DG) amorphous, indium-gallium-zinc oxide (a-IGZO) thin-film transistor (TFT) with an offset top-gate (TG) is reported. Given that both gates are opaque and electrically tied together, the TG functions as a lightshield drain-current (IDS) enhancer synchronized gate-voltage (VGS) sweep induces bulk-accumulation (BA) at positive voltages. It demonstrated here regardless of offsets between source/drain electrode, this BA a-IGZO TFT immune to negative bias...

We report high performance p-type poly-Si thin-film transistors (TFTs) achieved by lateral grain growth of amorphous silicon (a-Si) using a continuous-wave blue diode laser wavelength 445 nm. The beam is efficiently absorbed into the a-Si film, such that full melting and crystallization in all thicknesses investigated, 50-200 TFTs fabricated with 75-, 100-, 125-nm-thick films laterally grown annealing exhibited field-effect mobility 108 ± 7, 104 9, 134 12 cm <sup...

In this study, a simple, efficient, and economical process is reported for the direct synthesis of carbon nanotube (CNT) field emitters on metal alloy. Given that CNT can be customized with ease compact cold emission devices, they are promising replacements thermionic in widely accessible X-ray source electron guns. High performance emitter samples were prepared optimized plasma conditions through plasma-enhanced chemical vapor deposition (PECVD) subsequently characterized by using scanning...