A method for fabricating a multilayer structure includes providing a mask on a device stack disposed on the substrate, the device stack comprising a first plurality of layers composed of a first layer type and a second layer type; directing first ions along a first direction forming a first non-zero angle of incidence with respect to a normal to a plane of the substrate, wherein a first sidewall is formed having a sidewall angle forming a first non-zero angle of inclination with respect to the normal, the first sidewall comprising a second plurality of layers from at least a portion of the first plurality of layers and composed of the first layer type and second layer type; and etching the second plurality of layers using a first selective etch wherein the first layer type is selectively etched with respect to the second layer type.