A DFT Study of Atomic Layer Etching of Amorphous Zinc Oxide with Acetylacetone and Its Fluorinated Derivatives

A combined quantum-chemical and molecular dynamics study of atomic layer etching of amorphous zinc oxide by β-diketones—acetylacetone, 1,1,1-trifluoroacetylacetone, and 1,1,1,5,5,5-hexafluoroacetylacetone—was carried out using the ORCA 6.0.1 and LAMMPS software packages. Within the framework of density functional theory at the PBE-D3BJ/def2-SVP level, the energy parameters of adsorption and desorption were investigated, and the induced surface stress was quantitatively evaluated. It has been found that acetylacetone induces the highest surface stress (1.62 eV) and enables spontaneous etching due to its low desorption energy (2.10 eV). The fluorinated derivatives exhibit a self-limiting interaction behavior: 1,1,1-trifluoroacetylacetone, with a desorption energy of 3.27 eV, induces a surface stress of 1.05 eV, while 1,1,1,5,5,5-hexafluoroacetylacetone causes the weakest effect on the surface structure (1.01 eV) with a desorption energy of 2.53 eV. The results suggest that 1,1,1-trifluoroacetylacetone can be considered the most suitable precursor for controlled atomic layer etching of zinc oxide.