Abstract: A process for removing a plurality of layers of different materials from a substrate having a silicon material base, at least one of said layers being a silicon oxide material and at least one other of said layers comprising a metal and the metal layer being located above the silicon oxide layer. The process includes the steps of treating the substrate with a series of chemical formulations adapted to successively remove the materials of the plurality of layers until the silicon material base is exposed, the silicon oxide layer being removed by treatment with HF, wherein the HF treatment to remove said silicon oxide layer comprises exposing the substrate to:initially, a dilute HF solution of no more than 1.0% concentration;subsequently, a concentrated HF solution of from about 2.5% to about 10% concentration; andfinally, a dilute HF solution of no more than 1.0% concentration.