High‐Performance Full‐Solution‐Processed Oxide Thin‐Film Transistor Arrays Fabricated by Ultrafast Scanning Diode Laser

Abstract

On the other hand, most previous reports in solutionprocessed TFTs are focused on the nonpatterned single TFT from spin coating, which have rather large channel length (>50 µm) through the thermal evaporation that it is not suitable for the application in high-resolution active-matrix displays. [11,12] Therefore, in order to make TFT more practical for the application, the full-solution-processed TFT arrays with channel lengths of less than 10 µm must be fabricated by the photolithographic-patterned technique. Furthermore, it is also noted that solution-processed TFTs have typical disadvantages of high temperature (>400 °C), long time and high cost, [13][14][15] the alternative approach to fabricate full-solution-processed TFT array is the fast and energy-efficient postprocessing method of the ultrafast scanning diode laser annealing (USDLA), which provide a viable solution for commercialization, especially for displays and circuits.Meanwhile, the TFT devices directly expose to the atmospheric environment, the ambient water (H 2 O) and oxygen (O 2 ) that diffuse into the active layer can accelerate degradation of the device stability. [16,17] Usually, a passivation layer is used to isolate the device from the external environment to achieve the effect of blocking H 2 O and O 2 , thereby improving the stability of the device. And the silicon oxide thin films are widely used for passivation material because of its advantages, such as wide band gap, low leakage current density, and high industrial compatibility. [18][19][20][21][22] In addition, TFTs are inevitably exposed to light environment (from ambient light, the backlight of liquid crystal display panels, or self-illumination of active-matrix organic light-emitting diode), the light sensitivity of oxide TFTs should be minimized to ensure the application in practical displays. [23,24] Especially for the full-solution-processed oxide TFT remains suffering from severe bias-stress instability. [20,23,25] So, it is necessary to improve the stability under bias illumination stress for the full-solution-processed oxide TFT.Accordingly, on the basis of our previous studies for the tungsten-zinc-tin-oxide (WZTO) active layer, [26] the indium-tin-oxide (ITO) electrodes and the hafnium-aluminum-oxide (HAO) gate dielectric layers are further investigated comprehensively to The full-solution-processed oxide thin-film transistor (TFT) array is successfully realized by using ultrafast scanning diode laser annealing (USDLA). It integrates all solution-processed functional thin films well, including low-electrical-resistivity transparent conductive indium-tin-oxide (ITO) thin film, high-k dielectric hafnium-aluminum-oxide (HAO) thin film, and high-quality semiconductor tungsten-zinc-tin-oxide (WZTO) thin film. And the stacked multilayer thin films as a whole exhibit a smooth surface with the root mean square (RMS) roughness of 0.293 nm. The full-solution-processed TFT array exhibits a uniform overall TFT device performance, the average values including subthreshold swing of 11...

Monolithic Use of Inert Gas for Highly Transparent and Conductive Indium Tin Oxide Thin Films

“…This overall pattern was a reliable predictor of the crystallinity of the ITO material under the growth conditions of our experiment [10,21,22]. Similar RMS roughness results were found using magnetron sputtering (0.546 nm) [23] and another deposition technique (0.293 nm) [24]. Alternatively, we can see higher RMS roughness values found by Rita M. Carvalho et al [25] and others [26][27][28] ranging between 3.9 nm up to 24.8 nm.…”

Performance Modulation of Printed Two-Dimensional GaOx Film Transistor Upon Annealing Treatment

“…As a result, the characteristics of gallium oxide as a channel layer in electronic devices can be modulated by controlling the defects in the material including oxygen vacancies and gallium gaps. Modifying material defects, annealing, and doping engineering are currently two more efficient means. − …”