Patent ID: 6887786

Claim:
A method of forming a barrier layer on a substrate, comprising: sputter-depositing a tantalum nitride layer on a substrate having: a metal feature formed on the substrate; a dielectric layer formed over the metal feature; and a via formed in the dielectric layer so as to expose the metal feature, the via having side walls and a bottom, and a width of about 0.18 microns or less; wherein the tantalum nitride layer is deposited on the side walls and bottom of the via and on a field region of the dielectric layer; and wherein the tantalum nitride layer has a thickness of at least about 200 angstroms on the field region of the dielectric layer upon completion of the sputter-depositing of the tantalum nitride layer, then back sputtering at least a portion of the tantalum nitride layer from the bottom of the via of the substrate; and sputter-depositing a tantalum layer on the substrate, the tantalum layer having a thickness of less than about 100 angstroms on the field region of the dielectric layer upon completion of the sputter-depositing of the tantalum layer; wherein sputter-depositing the tantalum nitride layer and sputter-depositing the tantalum layer are performed in a single chamber.