Compositions and methods for the selective etching of tantalum-containing films for wafer reclamation

Abstract

The present invention provides methods for selectively stripping tantalum-containing films from oxide surfaces using an etching composition including a fluoride ion source and an acidic oxidant. The etching composition exhibits a high degree of selectivity between tantalum-containing films and oxide films, such that the underlying oxide surface or film layer acts as a stop layer, thereby protecting the underlying substrate from the etching composition. Furthermore, the etching composition is effective at substantially at ambient temperature, thereby avoiding the potential safety concerns that may arise when chemicals are heated in manufacturing situations. Finally, in certain preferred embodiments, the etching composition may further comprise a non-acidic oxidant. In these embodiments of the invention the etching composition is useful to reclaim wafers having at least a portion of the wafer substrate exposed, eg., wafers bearing film stacks comprising TEOS.