A method includes performing a dry etch process to remove a portion of a first layer disposed on a second layer of a stack of alternating layers. The first layer includes a first material and the second layer includes a second material different from the first material, and the dry etch process forms a passivation layer including a byproduct on surfaces of the second material. A amount of first material of the portion of the first layer remains after performing the dry etch process, The method further includes introducing a halide gas to enhance the passivation layer on the surfaces of the second material.