Correlation between crystallinity and oxygen vacancy formation in In–Ga–Zn oxide

Hiramatsu, Tomoki; Nakashima, Miho; Kikuchi, Erumu; Ishihara, Noritaka; Tsubuku, Masashi; Dairiki, Koji; Yamazaki, Shunpei

doi:10.7567/jjap.55.021203

Cited by 23 publications

(20 citation statements)

References 26 publications

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“…Remarkable improvement of the device reliability for CAAC IGZO TFTs was observed, especially under the bias stress with illumination, and they believed that this came from lower defect density compared with the a-IGZO film [ 14 ]. Hiramatsu et al proposed that the high crystallinity of CAAC IGZO is important for the inhibition of oxygen vacancies, which play an important role in the characteristics of IGZO-based devices [ 15 ]. These features allow CAAC IGZO to be used as an ideal candidate for applications in traditional displays, and it is potentially useful for various other products, such as low-power displays, non-volatile memory devices, novel sensors and large-scale integrations [ 16 , 17 ].…”

Section: Introductionmentioning

confidence: 99%

Preparation and Properties of Crystalline IGZO Thin Films

Wang

Shen

et al. 2021

Membranes

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IGZO thin films can be used as active layers of thin-film transistors and have been widely studied. However, amorphous indium gallium zinc oxide (IGZO) fabricated at room temperature is vulnerable in subsequent manufacturing processes, such as etching and sputtering; this limits IGZO thin film transistors’ (TFTs) use in commercial products. In this paper, we prepared a c-axis crystallized IGZO thin film by Radio Frequency (RF) sputtering at 180 °C, with a 50% O2 ratio and 110 W power. XRD images show that the crystallized film has an obvious diffraction peak near 31°, and the spacing between the crystal surfaces was calculated to be ≈0.29 nm. The HRTEM map confirmed the above results. The stability of IGZO thin films was investigated by etching them with an acid solution. The crystalline IGZO films exhibited better acid corrosion resistance, and their anticorrosion performance was 74% higher than that of amorphous IGZO (a-IGZO) films, indicating the crystalline IGZO film can provide more stable performance in applications.

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Section: Introductionmentioning

confidence: 99%

Preparation and Properties of Crystalline IGZO Thin Films

Wang

Shen

et al. 2021

Membranes

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“…This c -axis-aligned crystalline (CAAC) phase can be deposited with physical vapor deposition (PVD) at deposition temperatures ( T d ) around 300 °C, which is remarkably lower than the crystallization temperature a-IGZO ( T d ∼ 600 °C ,, ). CAAC-IGZO is less sensitive for defect formation, resulting in improved performance and better reliability . Similar properties are also assigned to nanocrystalline (nc-)IGZO, another intermediate semicrystalline morphology without clear grain boundaries …”

Section: Introductionmentioning

confidence: 71%

Deposition, Characterization, and Performance of Spinel InGaZnO₄

Dekkers

Setten

Belmonte

et al. 2022

ACS Appl. Electron. Mater.

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Polycrystalline indium−gallium−zinc oxide (IGZO) in the spinel phase was obtained by physical vapor deposition (PVD), using reactive sputtering from an IGZO target with In/Ga/ Zn = 1:1:1 composition. The initial growth of spinel IGZO is investigated by X-ray diffraction measurements after annealing the film. Deposition of spinel IGZO initially starts as a mixed amorphous/c-axis-aligned crystalline (CAAC) film, after which a metastable spinel IGZO is formed. Using a template of polycrystalline spinel Ga 2 ZnO 4 , the growth of the spinel phase is immediately achieved and enables the electrical characterization of pure spinel IGZO channels in scaled thin-film field-effect transistors. The average effective channel field-effect mobility of spinel IGZO of 50 ± 10 cm 2 /(V s) is slightly higher than amorphous IGZO in the same devices. This is in line with a slightly lower effective electron mass, as is calculated with density functional theory. The calculated total energies and band gaps have similar values to CAAC-IGZO. This metastable nature identifies spinel IGZO as an intermediate phase before the onset of CAAC-IGZO formation during PVD. Spinel IGZO is an interesting alternative to amorphous IGZO (a-IGZO) and CAAC-IGZO because of potentially higher robustness to oxygen vacancy formation.

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“…Previous studies have shown the close relationship between crystallinity and OVs; the energy barrier for OV generation in amorphous phases is far lower than that in crystalline phases. 39 It is safe to say that the higher OV concentration in Ti 2.5 Nb 9 W 0.5 O 29 -36h originates from the lower crystallinity.…”

Section: ■ Results and Discussionmentioning

confidence: 96%

Reducing Crystallinity of Micrometer-Sized Titanium–Niobium Oxide through Cation Substitution for High-Rate Lithium Storage

Guo

Yan

et al. 2021

ACS Sustainable Chem. Eng.

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As promising anode materials for lithium-ion batteries, titanium− niobium oxides still suffer from the bottleneck of ion transport, which severely limits their practical usage. In this work, the ion-transport kinetics of micrometersized Ti 2 Nb 10 O 29 is improved by crystallinity mediation. The crystallinity of Ti 2 Nb 10 O 29 is intrinsically reduced through cation substitution (Nb 5+ → Ti 4+ and W 6+ ), with Ti 2.5 Nb 9 W 0.5 O 29 obtained. The amorphous phases not only optimize the ion transport through isotropic ion diffusion path but also introduce more oxygen vacancies, which can serve as nucleation sites for phase changing and improve electron conductivity. As a result, Ti 2.5 Nb 9 W 0.5 O 29 exhibits superior kinetics and remarkable rate performance. Even with large particle sizes from 5 to 20 μm, Ti 2.5 Nb 9 W 0.5 O 29 can achieve a reversible specific capacity of 110 mAh g −1 at a high current density of 10 A g −1 , much higher than Ti 2 Nb 10 O 29 (11.1 mAh g −1 ). This work provides a novel view for the development of practical, high-performance anode materials for LIBs.

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Correlation between crystallinity and oxygen vacancy formation in In–Ga–Zn oxide

Cited by 23 publications

References 26 publications

Preparation and Properties of Crystalline IGZO Thin Films

Preparation and Properties of Crystalline IGZO Thin Films

Deposition, Characterization, and Performance of Spinel InGaZnO₄

Reducing Crystallinity of Micrometer-Sized Titanium–Niobium Oxide through Cation Substitution for High-Rate Lithium Storage

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Correlation between crystallinity and oxygen vacancy formation in In–Ga–Zn oxide

Cited by 23 publications

References 26 publications

Preparation and Properties of Crystalline IGZO Thin Films

Preparation and Properties of Crystalline IGZO Thin Films

Deposition, Characterization, and Performance of Spinel InGaZnO4

Reducing Crystallinity of Micrometer-Sized Titanium–Niobium Oxide through Cation Substitution for High-Rate Lithium Storage

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Deposition, Characterization, and Performance of Spinel InGaZnO₄