High Mobility IZTO Thin‐Film Transistors Based on Spinel Phase Formation at Low Temperature through a Catalytic Chemical Reaction

Abstract

In this paper, In0.22ZnδSn0.78−δO1.89−δ (δ = 0.55) films with a single spinel phase are successfully grown at the low temperature of 300 °C through careful cation composition design and a catalytic chemical reaction. Thin‐film transistors (TFTs) with amorphous In0.22ZnδSn0.78−δO1.89−δ (δ = 0.55) channel layers have a reasonable mobility of 41.0 cm2 V−1 s−1 due to the synergic intercalation of In and Sn ions. In contrast, TFTs with polycrystalline spinel In0.22ZnδSn0.78−δO1.89−δ (δ = 0.55) channel layers, achieved through a metal‐induced crystallization at 300 °C, exhibit a remarkably high field‐effect mobility of ≈83.2 cm2 V−1 s−1 and excellent stability against external gate bias stress, which is attributed to the uniform formation of the highly ordered spinel phase. The relationships between cation composition, microstructure, and performance for the In2O3–ZnO–SnO2 ternary component system are investigated rigorously to attain in‐depth understanding of the roles of various crystalline phases, including spinel Zn2−ySn1−yIn2yO4 (y = 0.45), bixbyite In2−2xZnxInxO4 (x = 0.4), rutile SnO2, and a homologous compound of compound (ZnO)k(In2O3) (k = 5). This work concludes that the cubic spinel phase of Zn2−ySn1−yIn2yO4 (y = 0.45) film is a strong contender as a substitute for semiconducting polysilicon as a backplane channel ingredient for mobile active‐matrix organic light‐emitting diode displays.

Oxide and 2D TMD semiconductors for 3D DRAM cell transistors

“…Researchers have explored diverse compositional tuning to extend the application of OSs beyond a -IGZO, aiming to maximize mobility and to improve reliability. 21,22 Beyond IGZO, a variety of OSs with different combinations, including binary oxides (In 2 O 3 , ZnO), 23,24 ternary oxides (IGO, IZO), 25–27 and further combinations like IZTO 28 and IGZTO, 29 has been researched. It is noteworthy that the majority of research and development in the field of OS thin-film transistors (TFTs) has been directed towards their application in flat-panel displays, where the physical channel length tends to be longer, exceeding 1 μm.…”

“…This necessity stems from the comparatively lower mobility of OSs compared to crystalline silicon or TMD. Ongoing efforts to address this limitation involve the composition 34,35 and non-stoichiometry fine-tuning 25,28,36 and thickness scaling, 37,38 as evidenced by the average values presented in the referenced studies (see Table 1). Among various approaches, indium-rich substances such as In 2 O 3 or Sn-doped indium oxide (ITO) emerged as frontrunners in enhancing the on-current of OS FETs, ensuring 20 mA μm −1 in a GAA-structured In 2 O 3 nano-ribbon transistor.…”

Advances in mobility enhancement of ITZO thin-film transistors: a review

“…Although TFTs are typically prepared at low temperatures, Park et al's research provided initial insights into the mobility and stability of ITZO TFTs after crystallization. Wang et al [60] used a different approach called metal-induced crystallization (MIC) to crystallize ITZO. They coated a 15 nm layer of aluminum (Al) metal on the back-channel surface of the ITZO TFT and annealed it below 400 °C.…”

Strong Immunity to Drain-Induced Barrier Lowering in ALD-Grown Preferentially Oriented Indium Gallium Oxide Transistors

“…To date, numerous studies have been reported to increase the μ FE in oxide TFTs using various approaches such as Sn-doped InGaZnO (IGZO), − optimization of the cation composition, − crystallization, − heterojunctions, − dual-gate structures, adjusting channel thickness, and postdeposition annealing (PDA) temperature. , Among them, the crystallization via the PDA is one of the simplest and the most effective approaches to improve the μ FE . However, the crystallization of oxide semiconductors with a ZnO component is generally accomplished at a high temperature (>700 °C) due to its corner-sharing crystal configuration different from In 2 O 3 and Ga 2 O 3 with an edge-sharing configuration crystal structure .…”