Device having self-repair Cu barrier for solving barrier degradation due to Ru CMP

摘要

A method of forming a doped TaN Cu barrier adjacent to a Ru layer of a Cu interconnect structure and the resulting device are provided. Embodiments include forming a cavity in a SiO-based ILD; conformally forming a doped TaN layer in the cavity and over the ILD; conformally forming a Ru layer on the doped TaN layer; depositing Cu over the Ru layer and filling the cavity; planarizing the Cu, Ru layer, and doped TaN layer down to an upper surface of the ILD; forming a dielectric cap over the Cu, Ru layer, and doped TaN layer; and filling spaces formed between the dielectric cap and the doped TaN layer.

主权项

1. A device comprising:
a silicon oxide-based (SiO-based) interlayer dielectric (ILD), including a cavity; a doped tantalum nitride (TaN) layer conformally formed in the cavity of the SiO-based ILD; a ruthenium (Ru) layer conformally formed on the doped TaN layer; a copper (Cu) layer formed over the Ru layer, filling the cavity; a dielectric cap formed over the Cu, Ru, and doped TaN layers; and manganese silicate (MnxSiOy) or aluminum silicate (AlxSiOy) formed between the doped TaN layer and the dielectric cap and between the Ru layer and the SiO-based ILD.