Perspectives in nanoscale plasma etching: what are the ultimate limits?

Plasmas have been widely utilized to pattern various materials, from metals to semiconductors and oxides to polymers, for a vast array of applications. The interplay between physical, chemical and material properties that comprises the backbone of plasma etching is discussed in this perspective paper, with a focus on the needed tools and approaches to address the challenges facing plasma etching and to realize the desired pattern transfer fidelity at the nanoscale.