Ultimate limits of conventional barriers and liners-implications for the extendibility of copper metallization

As allowable layer thicknesses shrink to the nanometer scale, metallization is facing fundamental limitations in the ability to extend conventional copper metallization schemes. The use of novel materials in the barrier/liner/seed stack can offer some relaxation of these roadblocks. For example, the development of a directly-platable barrier, thus avoiding the need to deposit a liner and seed, could offer potential benefits for scaling of copper past the 22 nm generation. This talk will introduce some of these emerging options and describe their performance compared with conventional copper barrier seed-based interconnects.

Graphical abstractDirectly platable PEALD diffusion barriers extendible to ∼2 nm thickness for sub-45 nm damascene copper metallization.Figure optionsDownload full-size imageDownload as PowerPoint slide