Patent ID: 7544606

Claim:
A method of forming a semiconductor structure comprising: forming an opening in a low-k dielectric layer; forming a metal layer over the low-k dielectric layer and filling the opening using a planar-surface forming method, the metal layer having a substantially planar surface, wherein forming the metal layer is preceded by a two-step pretreatment, and wherein a first step of the two-step pretreatment is selected from the group consisting of removing native oxide and contamination using HNO 3 , removing native oxide and contamination using HF, removing native oxide and contamination using H 2 SO 4 , and removing native oxide and contamination using combinations thereof, and wherein a second step of the two-step pretreatment is selected from the group consisting essentially of a SCCO 2 treatment, a chemical cleaning using NH 4 F, and combinations thereof; and stress free polishing the metal layer, wherein the step of forming the metal layer and the step of stress free polishing the metal layer are performed in a single vacuum environment.