Silicon Cations Intermixed Indium Zinc Oxide Interface for High-Performance Thin-Film Transistors Using a Solution Process

Abstract

Solution-processed amorphous metal-oxide thin-film transistors (TFTs) utilizing an intermixed interface between a metal-oxide semiconductor and a dielectric layer are proposed. In-depth physical characterizations are carried out to verify the existence of the intermixed interface that is inevitably formed by interdiffusion of cations originated from a thermal process. In particular, when indium zinc oxide (IZO) semiconductor and silicon dioxide (SiO) dielectric layer are in contact and thermally processed, a Si intermixed IZO (Si/IZO) interface is created. On the basis of this concept, a high-performance Si/IZO TFT having both a field-effect mobility exceeding 10 cm V s and a on/off current ratio over 10 is successfully demonstrated.

Rapid and Reliable Formation of Highly Densified Bilayer Oxide Dielectrics on Silicon Substrates via DUV Photoactivation for Low-Voltage Solution-Processed Oxide Thin-Film Transistors

“…Because the effective radius of Al 3+ ion (0.039 nm) is larger than that of Si 4+ ion (0.026 nm), Al 3+ ions need higher activation energy for diffusion than Si 4+ ions. , Nonetheless, in the case of DUV irradiation, which can produce a moderate number of defects such as oxygen vacancies, the diffusion of metal ions can be substantially promoted. Indeed, this phenomenon could be more prominent with metal ions with relatively low work functions such as Al (4.06–4.26 eV) compared with Si (4.60–4.85 eV), as reported in the previous studies. − Therefore, we suppose that despite the low-temperature (150 °C) condition, a thicker AlSiO x interlayer can be formed efficiently by DUV-assisted metal ion diffusion into the silicate layer (see also Figure f) and efficient thermal conduction through the underlying silicon substrate.…”

Simultaneously Defined Semiconducting Channel Layer Using Electrohydrodynamic Jet Printing of a Passivation Layer for Oxide Thin-Film Transistors

“…Previously, the role of Si ions diffused from the gate insulator, as a carrier suppressing the dopant in indium–zinc oxide, was verified by our group . Likewise, the diffused Si ions in the ITO film likely modulate the carrier concentration of ITO.…”

P‐21: Selective modulation of electrical characteristics for transparent conducting oxides by electro‐hydro‐dynamic printing technology

“…Figure 5 shows TOF-SIMS results of ITO:Al2O3 film annealed at 400 o C. It was evident that Al and Si ions originated from Al2O3 and SiO2 layer have diffused into the ITO layer. Previously, we have verified the role of diffused Si ions as carrier suppressing dopants in indium-zinc oxide (IZO) [4]. Likewise, we believe that the Si ions in the ITO layer have successfully modulated the carrier concentration of ITO layer.…”

“…400 o C. In O 1s XPS depth profile of ITO layer, the spectra were deconvoluted into three curves centered at 530±0.2, 531±0.2, and 532±0.2 eV[4,6,7]. The 530±0.2 eV peak represents lattice oxygen related to In and Sn metal-oxide bonds (M-O).…”