METHOD FOR FORMATION OF EMBEDDED METAL IN SUBSTRATE

摘要

PURPOSE: To manufacture a buried conductor and a via having soft low resistivity metal capped with a hard protective heat resistant metal. CONSTITUTION: A conductive via or wire is formed by three stage process. Firstly, a soft low resistivity metal 12 is bonded onto a trench or via of a dielectric 10 from the surface to the lower point thereof. Next, the low resistivity metal 12 is coated with a hard metal 16 such as CVD tungsten, etc. Lastly the structure is planarized by chemical and mechanical polishing process. In such a constitution, the hard metal 16 fills the role of protecting the low resistivity metal 12 from the scratch or corrosion normally caused when the low resistivity metal 12 is brought into contact with the chemical and mechanical polishing slurry.