Method to improve reliability (EM and TDDB) with post silylation plasma treatment process for copper damascene structures

摘要

A method for semiconductor fabrication includes etching a via and a trench in a dielectric material to yield an etched surface. The dielectric material may have an ultra-low K value (e.g., a K-value of less than or equal to 2.4). The etched surface is then processed with a gas-phase silylation process to yield a silylated surface. The silylated surface is processed with a plasma treatment process to yield a plasma treated surface. The plasma treated surface, in turn, is processed with a dilute hydrofluoric acid before a conductive metal is deposited in the via and the trench. Inclusion of the plasma treatment process reduces hollow metal defects caused by the silylation process and increases reliability of metal interconnects and improves barrier metallization.