Techniques for selectively removing a metal or conductive material during processing of a semiconductor die for high-voltage applications are provided. In some embodiments, the techniques treat a metallized semiconductor die to transfer a feature from a patterned photoresist layer deposited on the metallized semiconductor die. In addition, the patterned metallized semiconductor die can be subjected to an etch process to remove an amount of metal according to the feature in the pattern, resulting in a treated metallized semiconductor die that defines an opening adjacent to at least a pair of neighboring metal interconnects in the die. The treated metallized semiconductor die can be further treated to backfill the opening with a dielectric material, resulting in a metallized semiconductor die having a backfilled dielectric member. Such a metallized semiconductor die can be further processed according to a process of record until metallization, after which additional selective removal of another amount of metal can be implemented. Semiconductor dies having neighboring metal interconnects separated by backfilled dielectric regions also are provided.