Effect of molecular backbone structure on vapor phase coupling reaction between diiso(thio)cyanates with diamines, diols, and dithiols

Raya, Shimeles Shumi; Ansari, Abu Saad; Kang, Sung Gu; Lee, Han‐Bo‐Ram; Shong, Bonggeun

doi:10.1016/j.porgcoat.2019.105509

Cited by 5 publications

(2 citation statements)

References 40 publications

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“…The DFT calculations were performed using the Gaussian 16 and Orca 4.0 programs. , The geometries were optimized using the dispersion-corrected B97-D3 functional with the def2-TZVP basis set for the H, C, O, B, Al, Ga, and In atoms and the def2-SVP basis set for Si. Both adsorbate and surface atoms were allowed to relax during optimization.…”

Section: Theoretical Methodsmentioning

confidence: 99%

Mechanistic Investigation on Thermal Atomic Layer Deposition of Group 13 Oxides

2020

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Atomic layer deposition (ALD), based on selflimiting surface reactions, has been proven as a superior deposition method for synthesis of nanoscale thin films. In the field of oxide ALD, alumina (Al 2 O 3 ) is the most widely and thoroughly studied, prominently through using trimethylaluminum (TMA) with water (H 2 O). However, there is less information about other group 13 element (B, Ga, and In) oxides using analogous trimethyl precursors. In this study, we investigate these precursors' detailed adsorption and oxidation mechanisms during thermal ALD using density functional theory (DFT). The hydroxyl-terminated surface is transformed to a methyl-terminated surface after reacting with the trimethyl precursors. For such reaction, the reactivity of trimethylboron is significantly lower than other precursors. Meanwhile, using H 2 O, oxidation of the surface methyl is facile only for −Al−CH 3 , and stronger oxidants such as H 2 O 2 or O 3 are required for the oxidation reactions during ALD of B, Ga, and In oxides.

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Section: Theoretical Methodsmentioning

confidence: 99%

Mechanistic Investigation on Thermal Atomic Layer Deposition of Group 13 Oxides

2020

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“…DFT calculations were performed using the Orca 5.0 software. 24 Geometries were optimized using the dispersion-corrected B3LYP functional, 25 and the def2-TZVP 26 basis set was applied for the atoms within the adsorbates (H, C, Cl, O, N, and Al), as well as for the subsurface Si atoms. During the optimization, all atoms within the adsorbate-cluster complex were allowed to relax.…”

Section: Computational Detailsmentioning

confidence: 99%

Thermal atomic layer deposition of aluminum oxide, nitride, and oxynitride: A mechanistic investigation

Aqueel Ahmed,

Hafiyyan,

Nurhidayati

et al. 2024

AIP Advances

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Atomic layer deposition (ALD) has been proven to be a versatile method for the deposition of thin films of various materials. It yields films with exceptional conformality and allows tunable film compositions with control of film thickness at the atomic level. Thin films of Al oxide, nitride, and oxynitride are deposited via ALD using Al(CH3)3 (TMA)/AlCl3 with H2O/NH3. Herein, surface chemical reactions are examined using density functional theory calculations to elucidate the adsorption, oxidation, and nitridation of precursors [TMA and AlCl3] as well as the mechanism controlling the composition of Al oxynitride thin films obtained through ALD. The hydrogen-terminated substrate surface is transformed into a CH3/Cl-terminated surface after the reaction with the TMA/AlCl3 precursors. The molecular adsorption of TMA occurs through a spontaneous reaction, whereas that of AlCl3 requires a slight energy input. Although the adsorption energy of AlCl3 is higher than that of TMA, the activation energy and energy change of AlCl3 adsorption are higher and lower than those of TMA, respectively; furthermore, the use of AlCl3 results in the generation of a corrosive by-product (HCl). A similar tendency is observed in the second ALD half reaction, which is oxidation. Nitride formation is endothermic for molecularly adsorbed AlCl3 but exothermic for TMA. Furthermore, the investigation of the exchange reactions between surface moieties and excess gaseous reactants reveals a preference for the substitution of N by O, which is attributed to differences in bond energies between the surface moieties and the surface metal atom, as well as between H2O and NH3.

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