COMPOSITIONS AND PROCESSES FOR SPIN ETCH PLANARIZATION

摘要

The present invention describes methods and chemical compositions for the spin etch planarization of surfaces, particularly copper and tantalum. An etching solution is brought into contact with the upper face of a spinning wafer through a nozzle, preferably an oscillating nozzle. The etching solution has a composition that oxidizes the spinning surface, forming a passivation layer thereon. The etching solution further contains reactants for removing the passivation layer exposing the underlying surface to further reaction, leading to the desired etching of the surface. The characteristics of the etching solution are adjusted such that reactant diffusion to lower regions of the surface limits the rate of etching. Faster reaction occurs at higher regions of the surface lying in more rapidly moving etching solution resulting in the desired planarization.