Integration of Electrochemically Deposited Cu with Plasma Enhanced Atomic Layer Deposition-Grown Cu Seed Layers

A promising plasma enhanced atomic layer deposition (PEALD) Cu process has been developed, and PEALD Cu layers have been investigated for use in multilevel damascene metallization. Continuous and conformal PEALD Cu layers as thin as 12 nm were deposited on blanket and high aspect ratio patterned substrates. The effects of hydrogen plasma pretreatments on the material and integration properties of the PEALD Cu process have been studied. Plasma pretreatments were observed to improve Cu nucleation and enable lower Cu resistivity and surface roughness. Void-free electrochemically deposited Cu fill was achieved on PEALD Cu-seeded high aspect ratio via structures. The plated Cu films possess a strong (111) texture inherited from the PEALD Cu seed layer.