Ab-initio study of SiF2 molecule adsorption on Si(001)-p(2 × 2) reconstructed surface

• Published in: Solid state communications Vol. 368
• Main Authors: Lounis, A., Bouamama, L., Mokrani, A., Ziane, A.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2023
• Subjects: Etching; Fluorine; NEB; Silicon; Etching; Silicon; NEB; Fluorine
• ISSN: 0038-1098; 1879-2766
• DOI: 10.1016/j.ssc.2023.115176

First-principles calculations are performed to investigate the relaxation and electronic properties of SiF2 molecule deposited on surface. The reconstructed Si(001)-p(2 × 2) surface, modeled using density functional theory method, forms the basis for our molecule adsorption study. Several adsorption configurations corresponding to different orientations of the molecule have been investigated. Both stable dissociative and non-dissociative adsorption are found. For the most stable configuration, the adsorption takes place without dissociation of the molecule whose silicon atom binds two atoms of the surface. The progressive decomposition process of SiF2 is also explored using the nudged elastic band (NEB) method. An important energy barrier is obtained for the SiF2 molecule decomposition as compared to that of the SiF molecule. This could explain the high percentage of the SiF2 volatile molecule observed experimentally during the fluoride plasma etching process on the Si(001) surface. •SiF2 molecule adsorption process on Si(001)-p(2 × 2) surface reconstructed surface have been studied.•The progressive decomposition process of SiF2 is explored.•An important energy barrier is obtained for the SiF2 decomposition as compared to that of the SiF molecule.