Effects of Bias, Pressure and Temperature in Plasma Damage ofUltra Low-k Films

摘要

One of the most critical challenges during the integration of porous low-k materials in ULSI devicesis their degradation during plasma treatments. Removal of the carbon containing hydrophobicgroups can occur during strip and cleaning processes when exposed to process radicals. Furthermoisture adsorption leads to the film degradation. In addition, the "field damage" caused by ionradiation during plasma processing can also be problematic. Although these effects are discussed inmany papers [1,2], the dominant factors of plasma damage are still a subject of intensivediscussions. It has been shown that 02 plasma cause damage manifested as undesirable chemicalmodification (carbon depletion), while H2 based plasmas have more complicated behavior. Someauthors report no effect in low-k films, others that it enhances the film properties, and othersindicate severe damage [2].