Buffered HF Etch Barrier
Original Publication Date: 1982-Dec-01
Included in the Prior Art Database: 2005-Feb-10
In an existing process for via etching it is the functional metallurgy itself that is relied upon to prevent the BHF (buffered hydrofluoric acid) etchant from attacking the material beneath the functional metallurgy. The etchant could, due to the over-etch employed in most processes, travel along grain boundaries or through discontinuities in the film and attack the underlying material, thereby causing either time zero fails or reliability fails in the field.