Methods for etch of metal and metal-oxide films

A method of selectively etching a metal-containing film from a substrate comprising a metal-containing layer and a silicon oxide layer, the method comprising:

• flowing a fluorine-containing gas into a plasma generation region of a substrate processing chamber, wherein the plasma generation region is fluidly coupled with but physically separate from a substrate processing region of the substrate processing chamber;
• applying energy to the fluorine-containing gas to generate a plasma in the plasma generation region, the plasma comprising fluorine radicals and fluorine ions;
• filtering the plasma to provide a reactive gas having a higher concentration of fluorine radicals than fluorine ions, wherein the fluorine ions are eliminated traveling through an ion suppression plate from the plasma generation region to the substrate;
• flowing the reactive gas into a gas reaction region of the substrate processing chamber through a showerhead;
• and
• exposing the substrate to the reactive gas in the gas reaction region of the substrate processing chamber, wherein the reactive gas etches the metal-containing layer at a higher etch rate than the reactive gas etches the silicon oxide layer, wherein the ion suppression plate is positioned between the plasma generation region and the showerhead, wherein the gas reaction region is substantially plasma free during the etching operation, wherein the plasma generated is a capacitively-coupled plasma, and wherein at least one of the ion suppression plate or the showerhead comprises an electrode used to generate the plasma.