An electric field-assisted photochemical metal–organic deposition allowing control of oxygen content for resistive switching in directly patterned TiOx films

Recently the possibility of using electric fields as a further stimulus to trigger structural changes in metal-organic frameworks (MOFs) has been investigated. In general, rotatable groups or other types of mechanical motion can be driven by electric fields. In this study we demonstrate how the electric response of MOFs can be tuned by adding rotatable dipolar linkers, generating a material that exhibits paralectric behavior in two dimensions and dielectric behavior in one dimension. The suitability of four different methods to compute the relative permittivity κ by means of molecular dynamics simulations was validated. The dependency of the permittivity on temperature T and dipole strength μ was determined. It was found that the herein investigated systems exhibit a high degree of tunability and substantially larger dielectric constants as expected for MOFs in general. The temperature dependency of κ obeys the Curie-Weiss law. In addition, the influence of dipolar linkers on the electric field induced breathing behavior was investigated. With increasing dipole moment, lower field strength are required to trigger the contraction. These investigations set the stage for an application of such systems as dielectric sensors, order-disorder ferroelectrics or any scenario where movable dipolar fragments respond to external electric fields.

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Analysis of Threshold Voltage Shift for Full VGS/VDS/Oxygen-Content Span under Positive Bias Stress in Bottom-Gate Amorphous InGaZnO Thin-Film Transistors

Micromachines ◽

10.3390/mi12030327 ◽

2021 ◽

Vol 12 (3) ◽

pp. 327

Author(s):

Je-Hyuk Kim ◽

Jun Tae Jang ◽

Jong-Ho Bae ◽

Sung-Jin Choi ◽

Dong Myong Kim ◽

...

Keyword(s):

Thin Film ◽

Electric Field ◽

Oxygen Content ◽

Threshold Voltage ◽

Thin Film Transistors ◽

Electron Trapping ◽

Threshold Voltage Shift ◽

Voltage Shift ◽

Drain Side ◽

Bottom Gate

In this study, we analyzed the threshold voltage shift characteristics of bottom-gate amorphous indium-gallium-zinc-oxide (IGZO) thin-film transistors (TFTs) under a wide range of positive stress voltages. We investigated four mechanisms: electron trapping at the gate insulator layer by a vertical electric field, electron trapping at the drain-side GI layer by hot-carrier injection, hole trapping at the source-side etch-stop layer by impact ionization, and donor-like state creation in the drain-side IGZO layer by a lateral electric field. To accurately analyze each mechanism, the local threshold voltages of the source and drain sides were measured by forward and reverse read-out. By using contour maps of the threshold voltage shift, we investigated which mechanism was dominant in various gate and drain stress voltage pairs. In addition, we investigated the effect of the oxygen content of the IGZO layer on the positive stress-induced threshold voltage shift. For oxygen-rich devices and oxygen-poor devices, the threshold voltage shift as well as the change in the density of states were analyzed.

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Properties of Tin Oxide Films Prepared by MOCVD

Materials Science Forum ◽

10.4028/www.scientific.net/msf.449-452.997 ◽

2004 ◽

Vol 449-452 ◽

pp. 997-1000 ◽

Cited By ~ 3

Author(s):

Gwang Pyo Choi ◽

Yong Joo Park ◽

Whyo Sup Noh ◽

Jin Seong Park

Keyword(s):

Thin Films ◽

Oxygen Content ◽

Tin Oxide ◽

Vapor Deposition ◽

Chemical Vapor ◽

Organic Chemical ◽

Metal Organic ◽

Organic Chemical Vapor Deposition ◽

Tin Oxide Films ◽

N2 Annealing

Tin oxide thin films were deposited at 375 °C on α-alumina substrate by metal-organic chemical vapor deposition (MOCVD) process. A number of hillocks on the film were formed after air annealing at 500 °C for 30 min and few things in N2 annealing. The oxygen content and the binding energy after air annealing came to close the stoichiometric SnO2. The cauliflower hillocks of the film seem to be formed by the continuous migration of crystallites from a cauliflower grain on the substrate to release the stress due to the increase of oxygen content and volume.

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