Comparison of Barrier Efficiency for Self-Assembled Monolayers on SiO₂ by Using Decyltrimethoxysilane or 3-Aminopropyltrimethoxysilane Vapor Treatment

Self-assembled monolayers (SAMs) are the emerging materials as the candidate of barriers used in back-end-of-line interconnects for future generation. In this study, SAMs were formed on the SiO2 film by using decyltrimethoxysilane (DTMOS) or 3-aminopropyltrimethoxysilane (APTMS) in the vapor phase at a temperature of 100 degrees C. Barrier efficiency of the formation SAMS at the surface of SiO2 films under thermal and electrical stress was investigated from the perspective of the electrical characteristics. The formation of SAMs onto the SiO2 films by DTMOS and APTMS vapor treatment enhanced the adhesion, dielectric breakdown field and barrier against Cu migration under thermal stress. Additionally, APTMS-SAMs had a larger improvement. Under electrical stress with field larger than 6.5 MV cm-1, DTMOS-SAMs lost barrier effectiveness due to weak bonding structure. APTMS-SAMs still had the barrier capacity.