Embodiments of the present disclosure relate to precision material modification of three dimensional (3D) features or advanced processing techniques. Directional ion implantation methods are utilized to selectively modify desired regions of a material layer to improve etch characteristics of the modified material. For example, a modified region of a material layer may exhibit improved etch selectivity relative to an unmodified region of the material layer. Methods described herein are useful for manufacturing 3D hardmasks which may be advantageously utilized in various integration schemes, such as fin isolation and gate-all-around, among others. Multiple directional ion implantation processes may also be utilized to form dopant gradient profiles within a modified layer to further influence etching processes.