Impact of the Source/Drain Electrode Process on the Mobility-Threshold Trade-Off for InSnZnO Thin-Film Transistors

Abstract

In this work, the source/drain (S/D) electrode process is considered to have a great impact on the mobility (μ FE )− threshold (V th ) trade-off for high-mobility amorphous oxide semiconductor (AOS) thin-film transistors. High-mobility AOS materials have worse oxygen-fixation ability compared to InGaZnO. In this work, we show that this is the case for the Mo S/D electrode process on InSnZnO channels and has a great impact on the mobility-threshold trade-off. Oxygen vacancy gradients are observed in the depth profile X-ray photoelectron spectroscopy analysis on InSnZnO after Mo S/D deposition and show a bigger change in oxygen vacancies (V O ) between the surface and inner layers and thicker compared to InGaZnO. This leads to an obvious negative shift in V th or even no switching characteristic. Postprocessing such as oxygen-plasma treatment can make V th positive but degrade the μ FE . In situ replenishing oxygen via adopting ITO S/D electrodes deposited in an oxygen-containing atmosphere facilitates the achievement of excellent overall electrical characteristics, with μ FE up to 87.1 cm 2 /Vs, V th ∼ −0.64 V, and I on /I off ∼ 2.3 × 10 8 .

Effect of In-Situ H Doping on the Electrical Properties of In2O3 Thin-Film Transistors

“…Gaussian fitting is employed to deconvolute the O 1s peaks. The lowest binding energy Gaussian peak (O L ) at 529.8 eV originates from metal-oxygen bonds (M-O lattice); the peak at the middle binding energy 530.7 eV (O M ) is linked to O 2− ions of oxygen defects, such as V O ; while the highest binding energy Gaussian peak (O H ) at 531.9 eV is usually associated with specific chemisorbed oxygen such as -CO 3 , -OH, and H 2 O [34][35][36]. The area percentages of the three O peaks were calculated and are summarized in Table 1.…”

“…binding energy 530.7 eV (OM) is linked to O 2− ions of oxygen defects, such as VO; while the highest binding energy Gaussian peak (OH) at 531.9 eV is usually associated with specific chemisorbed oxygen such as -CO3, -OH, and H2O [34][35][36]. The area percentages of the three O peaks were calculated and are summarized in Table 1.…”

Polydopamine‐Enabled Biomimetic Surface Engineering of Materials: New Insights and Promising Applications

“…the applicability of modified surfaces, making them suitable for a wide range of practical applications such as electrochemical energy storage, conversion, conversion, photothermal therapy, bioengineering, adhesives, separation, purification, sensors, environment protection. [237][238][239][240][241][242][243][244][245][246][247] Moreover, the DA polymerization technique of PDA deposition is quite straightforward, costeffective, has a material-independent coating ability and does not require high-maintenance sophisticated instruments, unlike many other thin film deposition techniques. [237] A good adhesion can also be observed between the substrate and thin film in the DA assisted modification technique.…”

Origin of the High Density of Oxygen Vacancies at the Back Channel of Back-Channel-Etched a-InGaZnO Thin-Film Transistors

“…One is that the chemical reactions between the etchant and metal–oxygen bonds of a-IGZO film could occur and induce the Vo defects during the wet etching process of source/drain (S/D) electrodes [ 19 ]. The other one is that the magnetron sputtered deposition process of S/D metal could lead to the formation of Vo defects due to the strong ion bombardment [ 20 ]. However, these two mechanisms have not yet been experimentally confirmed, and the origin of the high density of Vo defects is still unclear.…”