Embodiments of the present disclosure provide methods for forming features in a film stack. The film stack may be utilized to form stair-like structures with accurate profiles control in manufacturing three dimensional (3D) stacking of semiconductor chips. In one example, a method includes exposing a substrate having a multi-material layer formed thereon to radicals of a remote plasma to form one or more features through the multi-material layer, the one or more features exposing a portion of a top surface of the substrate, and the multi-material layer comprising alternating layers of a first layer and a second layer, wherein the remote plasma is formed from an etching gas mixture comprising a fluorine-containing chemistry, and wherein the process chamber is maintained at a pressure of about 2 Torr to about 20 Torr and a temperature of about −100° C. to about 100° C.