A theoretical study on the surface reaction of tetrakis(dimethylamino)titanium on titanium oxide

Hye-Lee Kim; Romel Hidayat; Khabib Khumaini; Won-Jun Lee

doi:10.1039/d3cp02009f

A theoretical study on the surface reaction of tetrakis(dimethylamino)titanium on titanium oxide

Phys Chem Chem Phys. 2023 Aug 23;25(33):22250-22257. doi: 10.1039/d3cp02009f.

Authors

Hye-Lee Kim^{1

2}, Romel Hidayat^{1

2}, Khabib Khumaini^{2

3}, Won-Jun Lee^{1

2}

Affiliations

¹ Metal-organic Compounds Materials Research Center, Sejong University, Seoul, 05006, Republic of Korea. wjlee@sejong.ac.kr.
² Departments of Nanotechnology and Advanced Materials Engineering, Sejong University, Seoul, 05006, Republic of Korea.
³ Department of Chemistry, Universitas Pertamina, Jakarta 12220, Indonesia.

PMID: 37577845
DOI: 10.1039/d3cp02009f

Abstract

Tetrakis(dimethylamino)-titanium (TDMAT, Ti(NMe₂)₄) has been used for the low-temperature atomic layer deposition (ALD) process of titanium oxide (TiO₂) films. In this study, the chemisorption of TDMAT on a titanium oxide surface using a slab model was simulated by density functional theory (DFT) calculation. We calculated the activation energy for the chemisorption and predicted the final chemisorbed species. A TiO₂ slab model was constructed with the optimized number of -OH surface groups. Three serial ligand exchange reactions between a TDMAT molecule and the TiO₂ slab were exothermic with low activation energies of 0.16-0.46 eV, which can explain the low processing temperatures of the ALD TiO₂ processes. Our DFT calculation showed that three NMe₂ ligands of TDMAT would be released and the surface species of -TiNMe₂ would be formed, which is in good agreement with the experimental observation in the literature.