Impact of UV/O3 treatment on solution-processed amorphous InGaZnO4 thin-film transistors

Abstract

Ultraviolet–ozone (UV/O3) treatment was adopted to the fabrication of solution-processed amorphous In–Ga–Zn–O thin-film transistors (TFTs), with metal composition of In:Ga:Zn = 1:1:1 represented by InGaZnO4. By applying UV/O3 treatment In–Ga–Zn–O gel films, their condensation was notably enhanced through decomposition of organic- and hydrogen-based elements, which drastically improved the quality of the amorphous InGaZnO4 films. As a result, high TFT performance, with values of on/off ratio, 108; subthreshold swing, 150 mV/decade; threshold voltage, 9.2 V; and field-effect mobility, 5.1 cm2 V−1 s−1, was achieved.

Rapid low-temperature processing of metal-oxide thin film transistors with combined far ultraviolet and thermal annealing

“…As a contrast to the previous work performed with DUV light, 5,13,15,16 the linear extinction coefficient of water is several orders of magnitude (>10 3 ) larger at 160 nm than at 185 nm, leading to more efficient light absorption in H 2 O via the FUV exposure. 17,18 The FUV light energy at 748 kJ/ mol (k ¼ 160 nm) used in this work can induce the photolysis of water by breaking water molecules at a high quantum yield and produce atomic hydrogen (H*) and hydroxyl radicals (HO*) via a process that is nearly absent with k > 185 nm 17,19 …”

“…Downloaded to IP: pre-annealing, 15 annealing, 5,13 and post-annealing steps. 16 In our work, we have focused on shorter UV wavelength of 160 nm using a deuterium source since it is expected that such a short wavelength can introduce enhanced UV absorption and hydroxyl radical generation through the photolysis of water [17][18][19] as discussed in more detail in what follows.…”

Solution-processed yttrium oxide dielectric for high-performance IZO thin-film transistors

“…The peaks at 1565 and 1454 cm -1 observed in the thin film without treatment show symmetric and asymmetric vibrations of C=O and C-C banding [9]. This bonding suppresses the condensation of the oxide gel films by chelating with coordination banding to the metal cations [28].…”

“…It was reported that the content of indium had strong influence on mobility, and the presence of Zn in IZO thin films does not significantly contribute to the mobility. However, it is considered to enhance the amorphous phase stability of IZO thin films [8,9].…”

Controllable film densification and interface flatness for high-performance amorphous indium oxide based thin film transistors

“…[27][28][29][30][31][32][33] For instance, the a-IGZO TFTs used in most prototype displays were subjected to a thermal annealing process over 300 C to improve mobility, hysteresis, and stability. 28 Thus, the thermal annealing processes at different temperatures [27][28][29] and under various atmospheres such as in air, 7 N 2 , 10 O 2 , 30 moisture, 1 and O 3 32 have been investigated and found to greatly influence the transistors' performance.…”