Self-assembled monolayers on porous low-k dielectrics by decyltrimethoxysilane vapor treatment: A perspective from electrical characteristics and time-dependence-dielectric-breakdown reliability

Abstract

Self-assembled monolayer (SAM) is an attractive technology for back-end-of–line interconnects of integrated circuits for advanced technological nodes. In this study, SAMs were formed on the porous low-k films by decyltrimethoxysilane (DTMOS) in vapor phase at different temperatures. The effects of the formation SAMs on the electrical characteristics and reliability of the porous low-k films were characterized. With DTMOS vapor treatment at 50°C∼100°C, SAMs were formed onto the porous low-k films, thus enhancing the dielectric breakdown field, failure time, and Cu barrier capacity. Additionally, DTMOS vapor treatment at higher temperatures resulted in larger enhancement and more thermal stability. The formation SAMs was demonstrated to effectively repair the damaged porous low-k film, thus reducing the dielectric constant; although, the bulk dielectric constant was higher than that of the pristine film. To sum up, this study provided a promising SAMs processing derived from DTMOS vapor phase, for ensuring better integrity for the porous low-k films in the advanced technological nodes.