Method to reduce silanol and improve barrier properties in low K dielectric IC interconnects

摘要

A trench and via structure is formed in a low k dielectric layer ( 100 ) formed over a silicon substrate ( 10 ). Super critical CO₂ and a first silylization agent are used to form a chemically bonded high density surface layer ( 160 ). Silanol species are removed from the low k dielectric layer ( 100 ) using super critical CO₂ and a second silylization agent. A barrier layer ( 190 ) and copper ( 200 ) are used to fill the trench and via structure.