SELF- ASSEMBLED MONOLAYERS (SAM) BARRIERS DEPOSITED AT ELEVATED TEMPERATURES FOR SUB-22NM COPPER METALLIZATION

Self-Assembled Monolayers (SAMs) have been demonstrated as an attractive alternative to the conventional for preserving the integrity of metal-dielectric interfaces for Cu metallization. The SAM organo- silane molecules are assembled spontaneously in a 2D structure which is formed by the chemical bonding of those molecules onto the solid surface, in a process which is commonly referred as “Silanization”. A fast and safe process of Silanization of the SAM barriers (1~2nm) for Cu metallization is employed on bare-Si, thermal oxide and Low-k dielectrics. Current Silanization methods are hazardous and slow in mass scale manufacturing. In this work, we describe a novel process, using high flash point solvents (i.e. NMP, Ethelene glycol) allowing higher deposition temperature and shorter deposition time allowing higher throughput. In this research, we discuss the use of various silane monomers.

Metal/insulator/silicon structures were formed by Cu evaporation on the SAM/ILD/Si for checking the effect of 400°C anneal for 1h on the barrier integrity. The ultra-thin films have been characterized by contact angle measurements, Spectroscopic ellipsometry, XPS, SIMS, and AFM .

The barrier properties show that this SAM barrier manufactures by the novel process can be applied as barriers for ULSI for Cu-low-k/Si metallization.