US Patent 7419609 Method for quantifying over-etch of a conductive feature

The invention provides a method for quantifying over-etch of a conductive feature. In one embodiment, this method includes forming a conductive feature over a substrate, the conductive feature having a sheet resistance test structure associated therewith, the sheet resistance test structure having a first sheet resistance value. This method may further include etching the conductive feature and the sheet resistance test structure using a common etch process, obtaining a second sheet resistance value of the sheet resistance test structure after the etching, and quantifying an amount of over-etch into the conductive feature using the first and second sheet resistance values.