SiO2 etch rate modification by ion implantation

The structural damage of silicon dioxide films produced by different ion species has been studied by etch rate profiling. The etch rate showed a good correlation with the damage estimated by a simulation software. The etch rate increases almost linearly up to a certain damage level then it saturates to a value which depends on the implanted ion and on the etching chemistry. This suggests a different kind of damage mechanism induced by the different implanted ions.

► SiO2 etch rate increases linearly up to a threshold damage level.
► After this threshold, the etch rate does not increase significantly.
► The saturation level depends on the implanted specie.
► A single parameter allows modeling different etching chemistries.