Method of fabricating a semiconductor work object

A method of forming a conductive plug in a contact hole comprising: providing a wafer having a conductive layer comprising silicon adjacent a dielectric layer comprising silicon oxide, and a contact hole disposed in the dielectric layer, the contact hole having surfaces that include sidewalls formed in the dielectric layer and a bottom defined by the conductive layer, a contaminant material being disposed over at least a portion of the conductive layer defining the bottom of the contact hole, the dielectric layer having a surface in which the contact hole terminates in an opening opposing the bottom; depositing a layer of a barrier material on the work object, the layer having a substantially uniform thickness from the surface at the opening of the contact hole to the bottom of the contact hole; and depositing a layer of a protective material barrier around at least opening of the contact hole; etching the material at the bottom of the contact hole to expose the contaminant material while retaining protective material around the opening of the contact hole; etching the contact hole to remove contaminant material disposed over the conductive layer at the bottom of the contact hole; and filling the contact hole with a conductive material to form a plug.