Method for removing a first feature comprising a Sn-containing first Group IV material selective to a second feature comprising a second Group IV material, the method comprising: providing, in a process chamber, a substrate having an upper surface, wherein the first feature and the second feature are arranged on the upper surface, wherein the Sn-containing first Group IV material comprises a dopant element; heating, in the process chamber, the substrate, and thereafter; performing an etch process comprising: introducing, into the process chamber, an etching gas, subjecting the substrate to theetching gas, wherein the etching gas is a chlorine-based or a bromine-based gas.