Effect of direct current sputtering power on the behavior of amorphous indium-gallium-zinc-oxide thin-film transistors under negative bias illumination stress: A combination of experimental analyses and device simulation

Abstract

Articles you may be interested inChannel length dependence of negative-bias-illumination-stress in amorphous-indium-gallium-zinc-oxide thin-film transistors

Carbohydrate-Assisted Combustion Synthesis To Realize High-Performance Oxide Transistors

“…Flat panel displays encompass a growing number of electronic visual technologies and are far lighter, thinner, and of higher resolution than conventional designs. − Although amorphous silicon (a-Si:H) is typically used in thin-film switching transistors (TFTs) for active-matrix liquid crystal displays (AMLCDs) or active-matrix organic light-emitting diode displays (AMOLEDs), − it is limited by low field-effect mobility (∼0.5–1.0 cm 2 V –1 s –1 ) and poor current-carrying properties. − Thus, low-temperature (≤600 °C) poly-silicon (LTPS) TFTs fabricated on glass substrates, with mobility >50 cm 2 V –1 s –1 and good current-carrying properties, are attractive for next-generation display technologies. − However, LTPS TFT production is capital- and energy-intensive, and the resulting TFTs exhibit poor electrical uniformity and high off-current levels. − Significant research carried out on amorphous metal oxide semiconductors (AOSs) has demonstrated that they are promising alternatives to LTPS. − Due to their outstanding electrical properties, excellent optical transparency, and remarkable mechanical flexibility, a-MO TFTs with mobilities of ∼5–10 cm 2 V –1 s –1 , achieved by sputtering indium-gallium-zinc oxide (IGZO) films, have reached large-scale manufacture. − More recently, with the aims of lowering processing temperatures, reducing production costs, and enabling high-throughput deposition by printing on plastic substrates, solution-processed a-MO TFTs, and particularly those based on IGZO, have advanced significantly. − In pioneering studies, solution-processed IGZO TFTs were realized at 150–250 °C using deep-UV irradiation, sol–gel on a chip, spray pyrolysis, high-pressure thermal annealing, and combustion synthesis. − However, the saturation mobilities of these devices on low-capacitance SiO 2 dielectrics remain modest (∼1–3 cm 2 V –1 s –1 ), with generally inferior bias-stress stability (5–10 V threshold voltage shift) versus state-of-the art sputtered IGZO TFTs. This likely reflects high defect densities and incomplete lattice densification.…”

Control of the Boundary between the Gradual and Abrupt Modulation of Resistance in the Schottky Barrier Tunneling-Modulated Amorphous Indium-Gallium-Zinc-Oxide Memristors for Neuromorphic Computing

“…) is the well-known metastable state [21,22] and has been frequently pointed out as having a microscopic origin on the device instability under photo-illumination or bias stress [22][23][24][25][26] and persistent photoconductivity [25,26]. From the viewpoint of the subgap density of states (DOSs) in the a-IGZO (Figure 4b), the neutral…”

Effects of Deposition Temperature on the Device Characteristics of Oxide Thin-Film Transistors Using In–Ga–Zn–O Active Channels Prepared by Atomic-Layer Deposition

“…Next, the NBIS of the devices were also investigated with varying the irradiation wavelengths. Under the negative-bias stress in dark conditions, the IGZO TFTs generally exhibit stable device characteristics owing to the n-type semiconducting nature of IGZO channel layer. − Contrarily, the V TH values of the IGZO TFTs might experience considerable amounts of negative shifts under the NBIS conditions, which is related to the fact that the donor states can be newly created in shallow levels and provide conduction electrons into the conduction bands. , Sometimes, the generated conduction electrons can also be trapped at the interface between the gate insulator and IGZO channel layers. The NBIS tests were performed under the light illuminations by using the light-emitting diodes with the wavelengths of 635 (red), 530 (green), and 470 nm (blue) corresponding to the energies of 1.95, 2.34, and 2.65 eV.…”