Comparison of the damage and contamination produced by CF4 and CF4/H2 reactive ion etching: The role of hydrogen

In this study, the damage and contamination effects of CF4 and CF4/H2 reactive ion etching of silicon are compared. Included for the first time is an electrical, structural, and compositional examination of etched silicon which establishes the material property modifications resulting from the incorporating of hydrogen into the reactive ion etching environment. The results of this comparison of CF4 and CF4/H2 etching show that, for the same etching parameters, the presence of hydrogen causes more structural damage in the etched Si surface. However, the hydrogen is found to passivate its own damage rendering it electrically inactive. Subsequent exposure to temperatures exceeding ∼450 °C removes the passivation.