Efficiency of oxygen plasma cleaning of reactive ion damaged silicon surfaces

Abstract
It is demonstrated with the use of in situ x‐ray photoemission spectroscopy, secondary ion mass spectrometry, and transmission electron microscopy, that the commonly practiced in situ oxygen plasma/hydrofluoric acid dip treatment of reactive ion damaged silicon surfaces is insufficient in removing all reactive ion etching (RIE) related contaminants and damage. For CHF3/CO2 RIE the residual modifications are shown to be fluorine and carbon contamination and deeper lying modifications, e.g., hydrogen‐induced extended Si defects. An enhanced silicon oxidation rate during air exposure has been observed for post‐RIE‐treated silicon, which correlates to the amount of residual fluorine.