Selective tantalum nitride deposition for barrier applications

A method of forming a semiconductor device interconnect, the method comprising:

• exposing a substrate with a feature formed therein to a blocking chemistry species to form a blocking layer, the feature formed in a dielectric layer on an etch stop layer, the feature having a via portion and a trench portion, the via portion exposing sidewalls of the dielectric layer, a sidewall of the etch stop layer and a bottom surface of the via portion being a top surface of a first metal layer, the trench portion exposing an upper sidewall and a bottom surface of the dielectric layer, the sidewall, bottom surface and upper sidewall of the dielectric layer having a dielectric surface, the sidewall of the etch stop layer having an etch stop layer surface comprising an aluminum oxide surface, the blocking chemistry species comprising at least one compound with a general formula R4−nSiHn, where R is selected from C1-C22 alkyl groups and n is 1 to 3, the blocking layer selectively forming on an exposed metal surface to a greater extent than on an exposed dielectric surface and an exposed aluminum oxide surface;
• forming a liner on the dielectric surface and the aluminum oxide surface;
• removing the blocking layer from the metal surface;
• and
• depositing a second metal on the metal surface and the liner on the dielectric surface and aluminum oxide surface.