Effects of H-2 plasma treatment on low dielectric constant methylsilsesquioxane

Abstract

The quality of organic low-k methylsilsesquioxane (MSQ) film is degraded by the damage of oxygen plasma and hygroscopic behavior during photoresist stripping. In addition, the interaction between MSQ and copper is worth investigating. In this work, we have studied the H-2 plasma treatment to improve the quality and enhance the copper penetration resistance of MSQ, Experimental results show the leakage current of MSQ decreases as the H-2 plasma treatment time is increased. The dielectric constant of treated samples also remains constant (similar to 2.7). In addition, the copper diffusion resistance of MSQ film is significantly promoted. The H-2 plasma treatment can provide additional hydrogen to passivate the inner structure of porous MSQ film as well as reduce the probability of moisture uptake and interaction with Cu atoms. Therefore, the low-k dielectric properties of MSQ are significantly enhanced by H-2 plasma treatment. (C) 1999 American Vacuum Society. [S0734-211X(99)05105-7].