Method for reducing surface charge on semiconductor wafers to prevent arcing during plasma deposition

摘要

A process of forming a layer of conductive material over a layer of insulating material is provided. A wafer is positioned on a wafer platform such that it is thermally and electrically coupled to the wafer platform. A clamping ring engages the peripheral edge of the wafer such that the wafer is held against the top surface of the wafer platform. The clamping ring is electrically coupled to the wafer pedestal. The wafer is exposed to a plasma comprising conductive material and an initial layer of conductive material is formed over the insulating layer until the top surface of the wafer is electrically coupled to the clamping ring. The wafer pedestal is then electrically biased and additional conductive material is formed. Once the initial layer of conductive material is electrically coupled to the clamping ring, the potential difference between the top and bottom surface of the wafer is zero such that arcing through the wafer is reduced. The wafer platform may also be exposed to the plasma so as to reduce the potential difference between the top and bottom surfaces of the wafer when the wafer platform is electrically biased.