Moisture influence on porous low-k reliability

In this paper, the impact of moisture on the reliability of porous low-k materials has been investigated. It was found that moisture uptake is higher for more porous SiOC low-k materials, and its presence inside the low-k has a strong impact on the dielectric reliability. It has been demonstrated that by eliminating moisture, the leakage current can be significantly decreased; in addition, higher breakdown electric fields and longer dielectric lifetimes can be achieved. Therefore, integration of porous low-k materials requires maximum attention to prevent moisture uptake at each step during integration; in addition, the passivation layers need to be perfectly hermetic in order to maintain good dielectric reliability.