ALD Barriers Show Promise, Not Perfection

摘要

At IEEE's latest International Intercon-nect Technology Conference (IITC) meeting, there were many hot topics in-cluding optical interconnects, cop-per/low-k integration and low-k packaging issues. But the burgeoning technology of atomic layer deposition (ALD or AL-CVD) stole the show for many attendees. ALD promises monolayer thickness control of ultrathin metal barrier and seed for copper interconnects. It is expected to take over when physical or chemical vapor deposition films can no longer meet conformality requirements of high-aspect-ratio vias and trenches ― possibly as soon as the 65 nm node. In addition, ALD brings to bear new material options. For instance, WN_xC_y is a promising diffusion barrier that features higher growth rates than TiN, adhesion to a variety of low-k materials as well as copper, and relatively low process temperatures (300-350℃).