Si-incorporated amorphous indium oxide thin-film transistors

Abstract

Amorphous oxide semiconductors, especially indium oxide-based (InOx) thin-films, have been major candidates for high mobility with easy-to-use device processability. As one of the dopants in InOx semiconductors, we proposed Si to design a thin-film transistor (TFT) channel. Because the suppression of unstable oxygen vacancies in InOx is crucial to maintaining the semiconducting behavior, Si was selected as a strong oxygen binder that is reasonably available for large production. In this review, we focus on the overall properties observed in Si-incorporated amorphous InOx TFTs in terms of bond-dissociation energy, Gibbs free energy, Si-concentration dependence of TFT properties, carrier transport mechanism, and bias stress instability. In comparing low and high doping densities, we found that the activation energy and density of states decreased at a high Si concentration in InOx TFTs, implying that the trap density was reduced. As a result, stable operation under bias stresses could be realized. Furthermore, the inverse Meyer-Neldel rule was observed in the highlySi-doped InOx TFT, indicating reasonable ohmic contact. Based on our fundamental knowledge of the Template for JJAP Regular Papers (Jan. 2014) 2Si-doped InOx film, we developed a high-mobility bilayer TFT with a homogeneous stacked channel that was different from a TFT with an etch stop layer structure. The TFT showed remarkably stable operation. With simple element components based on InOx, it is possible to systematically discuss vacancy engineering in terms of conduction properties.

Low voltage thin film transistors based on solution-processed In2O3:W. A remarkably stable semiconductor under negative and positive bias stress

“…To suppress crystallization, several reports on TFTs implementing semiconducting channels based on In2O3 have focused on InGaZnO, 4,5,6,7,8 InZrZnO, 9,10 InHfZnO, 11,12,13,14 InWZnO, 15 InSiZnO, 16,17 InScZnO, 18 InTaZnO, 19 InBZnO, 20 InCZnO, 21 InGaO, 22 InGeO, 23 InHfO, 24 InSiO, 25 , 26 InWO, 27 and InZnO, 28,29 however works on doped In2O3 have also been reported. 25,30,31,32,33,34 In most cases, those In2O3-based semiconductors have been processed by a large number of vacuum-based and potentially costly techniques such as Atomic Layer Deposition, Sputtering, Pulsed Laser deposition, and e-beam deposition. However there are a handful of reports where solution-based techniques such as inkjet 35 printing, and spray pyrolysis 36 , 37 have also been employed.…”

Amorphous NdIZO Thin Film Transistors with Contact-Resistance-Adjustable Cu S/D Electrodes

“…Low V G corresponds to high R C and high V G corresponds to low R C , which realizes the modulation of V G on R C and suggests that the NdIZO-TFTs have dynamic contact characteristics. When the annealing temperature is 300 °C, after extracting the intersection of the fitted lines at different V G s, a fixed value of 3.47 kΩ was obtained, which is similar to the contact situation of a highly doped device [ 37 , 38 , 39 , 40 , 41 , 42 , 43 ]. This also confirms the possibility that the carrier concentration increases with the increase in the annealing temperature.…”

Effects of Al Precursors on the Characteristics of Indium–Aluminum Oxide Semiconductor Grown by Plasma-Enhanced Atomic Layer Deposition

“…In addition, the IAO films also contained a few atomic % of silicon oxide (Figure S6, Supporting Information). The incorporation of Si atoms in InO x is also known to control the carriers by suppressing the formation of oxygen vacancies. − The Si dopants would have originated from the fragmentation of ligand in the INCA-1 precursor, as suggested by an almost constant ratio of Si to In (Si/In) in the InO x films regardless of the Al content. The binding energy of the In 3d peak gradually shifted to higher binding energy by adding Al, as shown in Figure b.…”