Cleaning composition containing tetraalkylammonium salt and use thereof in semiconductor fabrication

The present invention relates to semiconductor fabrication, and more particularly to removing residue from a semiconductor wafer that has been subjected to planarization. A composition prepared from water, hydrofluoric acid (HF) and tetraalkylammonium hydroxide (TAAH, preferably tetramethylammonium hydroxide (TMAH)) or tetraalkylammonium fluoride and solvent with or without HF or TAAH is used to clean residue from a semiconductor wafer, where the residue is formed as a result of a planarization process, such as chemical mechanical polishing. Incorporation of TMAH into an aqueous HF composition retards the rate at which the composition dissolves borophosphosilicate (BPSG) without effecting the rate at which silica is dissolved. Thus, the aqueous HF/TMAH composition may be used to completely remove silica-containing residue from a BPSG surface, with a tolerable level of BPSG removal.