The Synergistic Effect of N[sub 2]/H[sub 2] Gases in the Plasma Passivation of Siloxane-Based Low-k Polymer Films

This work examines the impact of the chemistry of the gas mixture and the plasma-related operating conditions on etching and/or passivation of siloxane-based polymer (HOSP) films. Plasmas generated using an inadequate power source and an -dominating chemistry tend to induce the removal of carbonaceous species and over-cross-linking from such a film's structure, sharply degrading the film's dielectric constant and insulating capacity. Nonetheless, properly adjusting the operating power supply and shifting the gas mixture toward the -dominant regime cause the plasma to outperform the commonly used and plasmas with respect to protecting the films against plasma damage, by forming a surface nitride layer.