Improving wet etching uniformity during spin-etching of a layer on a semiconductor wafer, by forming a water film on the wafer before acid etching of the layer

摘要

Wet etching uniformity is improved by forming a water film on a layer-bearing semiconductor wafer (10) before acid etching of the layer. An Independent claim is also included for a wet etching process comprising: application of deionized water onto a rotating layer-bearing semiconductor wafer (10) to form an aqueous film and application of an acid solution (40) to etch the layer before the water film dries. Preferred Features: The layer is a metallic layer (e.g. of copper or aluminum) or a non-metallic layer (e.g. silicon, silicon oxide, borophosphosilicate glass (BPSG), phosphosilicate glass (PSG), borosilicate glass (BSG). silicon nitride, silicon oxynitride or spin-on glass). The acid solution contains sulfuric, hydrofluoric, nitric, phosphoric and/or acetic acids.