Low dielectric constant materials: challenges of plasma damage

Degradation of porous low dielectric constant materials during their exposure in etch and strip plasmas is analyzed from point of view of surface chemistry and recombination of active radicals. Although the degree of damage during the etching can be significantly reduced, the damage in O₂ and H₂ based strip/cleaning plasma are more challenging. The plasma damage mechanisms are the main subject of this discussion. It is demonstrated why the degree of damage can be reduced using He and H₂ based plasmas at elevated processing temperature