Performance Improvement of ZnSnO Thin-Film Transistors with Low-Temperature Self-Combustion Reaction

Abstract

Conventional sol-gel solutions have received significant attention in thin-film transistor (TFT) manufacturing because of their advantages such as simple processing, large-scale applicability, and low cost. However, conventional sol-gel processed zinc tin oxide (ZTO) TFTs have a thermal limitation in that they require high annealing temperatures of more than 500 °C, which are incompatible with most flexible plastic substrates. In this study, to overcome the thermal limitation of conventional sol-gel processed ZTO TFTs, we demonstrated a ZTO TFT that was fabricated at low annealing temperatures of 350 °C using self-combustion. The optimized device exhibited satisfactory performance, with μsat of 4.72 cm2/V∙s, Vth of −1.28 V, SS of 0.86 V/decade, and ION/OFF of 1.70 × 106 at a low annealing temperature of 350 °C for one hour. To compare a conventional sol-gel processed ZTO TFT with the optimized device, thermogravimetric and differential thermal analyses (TG-DTA) and X-ray photoelectron spectroscopy (XPS) were implemented.

Performance improvement of a sol–gel ZTO-based TFT due to an interfacial SnOxdopant layer

“…For the solution-processed ZTO-based TFTs reported in the literature, the μ are 0.2–4.72 cm 2 V −1 s −1 , SS are 0.11–3.05 V dec −1 , V th are −1.28–21.5 V, I off are 10 −9 –10 −12 A and the I on / I off ratio is ∼10 6 . 29,30,80,81 For the Z/S/Z TFT proposed in this study, the μ is 14.33 cm 2 V −1 s −1 , SS is 0.13, V th is 0.8 V, I off is ∼10 −12 A and I on / I off ratio is 2.35 × 10 8 . Compared with the previously reported ZTO-based TFTs, the Z/S/Z TFT shows significant improvements in μ , SS, V th and I on / I off ratio.…”

High-Performance Amorphous InGaSnO Thin-Film Transistor with ZrAlOx Gate Insulator by Spray Pyrolysis

“…A higher M-O m ratio leads to an increase in the overlapping of the metal s orbitals [5,9,[13][14][15][16]. The increase in overlapping can clarify the higher field-effect mobility and excellent bias stability of the a-IGTO TFT.…”

“…Due to fever traps at the interface between GI/semiconductor, the TFT exhibits lower SS and a higher I ON , as shown in Figure 5b. Upon the Ga doping, the V TH shifts towards positive V GS due to gallium acting as a carrier killer since Ga + has a higher binding energy with oxygen [2,10,[13][14][15]26]. The decrease in the SS of IGTO TFT indicates the reduction in traps at the IGTO/ZAO interface.…”

“…To obtain highly stable, solution-processed multicomponent amorphous MOS TFTs, various MOS are studied by doping metal cations such as aluminum (Al), gallium (Ga), hafnium (Hf), lanthanum (La), magnesium (Mg), yttrium (Y), and zirconium (Zr) into ZnO, InO x , or IZO [2,10,[14][15][16]. The mixing of two or more metal cations with different ionic radii and ionic charges is adequate to have an amorphous phase by suppressing crystallization [2,5,10].…”

Light Effect on Amorphous Tin Oxide Thin‐Film Transistors

“…[4,[8][9][10][11][12] Yet, the drawbacks have been low mobility and/or high gate leakage currents. [13][14][15][16][17] High-temperature-annealed (over 300 °C) and/or spin-coated devices may compete with vacuum-processed TFTs. The development of solution-processed TFTs has been accompanied by high-k dielectrics, as they provide low-voltage operation and high mobilities.…”