Hydroxylamine, a weak inorganic amine, etches copper and is considered for use in the planarization (removal of topography) of copper films during the manufacturing of integrated circuits. This paper reports and discusses results obtained from a study on the dissolution behaviour of copper in hydroxylamine solutions at different applied anodic potential values using Quartz Crystal Microbalance (QCM) technique. The dissolution rate of copper in hydroxylamine solution is pH dependant and exhibits a maximum in the vicinity of pH 6. Copper dissolution increases with applied overpotential (η) and dissolution rates as high as 6000 å min- 1 can be obtained at overpotential of 750mV. While both benzotriazole (BTA) and salicylhydroxamic acid (SHA) serve as good inhibitors at lower overpotentials, their effectiveness decreases at higher overpotentials.