TY - JOUR
T1 - Thermal atomic layer deposition of aluminum oxide, nitride, and oxynitride
T2 - A mechanistic investigation
AU - Aqueel Ahmed, Abu Talha
AU - Hafiyyan, Afina faza
AU - Nurhidayati, Nurhidayati
AU - Hidayah Rayanisaputri, Fani Rahayu
AU - Alibrahim, Khuloud A.
AU - Khadtare, Shubhangi S.
AU - Rahman, Shofiur
AU - Alodhayb, Abdullah N.
AU - Rochman, Nurul Taufiqu
AU - Ansari, Abu Saad
N1 - Publisher Copyright:
© 2024 Author(s).
PY - 2024/3/1
Y1 - 2024/3/1
N2 - 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.
AB - 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.
UR - https://www.scopus.com/pages/publications/85188029368
U2 - 10.1063/5.0190183
DO - 10.1063/5.0190183
M3 - Article
AN - SCOPUS:85188029368
SN - 2158-3226
VL - 14
JO - AIP Advances
JF - AIP Advances
IS - 3
M1 - 035133
ER -