Experimental and numerical analysis of the effects of ion bombardment in silicon oxide (SiO_2) plasma enhanced atomic layer deposition (PEALD) processes

摘要

Reactions between a precursor-absorbed SiO2 surface and energetic ion species, i.e. Ar+ or O+ ions, in a plasma enhanced atomic layer deposition (PEALD) process were investigated using an in situ X-ray photoelectron spectrometer system and a molecular dynamics (MD) simulation. Both the experiment and simulation results showed that N and/or C atoms originating from the precursor molecules remained on the surface as amorphous carbon and/or cyanide after 50 eV ion bombardment. The precursor-originated atoms as well as the SiO2 film were removed by the incident ions when its energy increased to 100 eV, and exceedingly small amount remained on the surface. The MD simulation results showed that chemical effects had a more obvious effect on the removal of C atoms at lower incident energies, while purely physical effects dominated at high O+ ion incident energies. These results indicated the importance of ion energy in PEALD processes in terms of film quality. (C) 2020 The Japan Society of Applied Physics