Etch processes have always involved inherent process trade-offs related to fundamental plasma parameters to achieve planar patterning metrics related to damage, aspect ratio dependences and profile. Today, we are in a new era of "area selective etch." Advanced patterning (SAXP, (LELE) n), logic, memory and interconnect applications beyond 3 nm involve, in one way or another, topographies that require etch "control" at every surface. Achieving profile specifications will require the ability to conjure isotropy control at will. Vehicles to achieving this include novel precursors and hybrid processes involving combinations of deposition and plasma etch as we know it. Ultimately, to differentiate surfaces comprising silicon, silicon oxides and nitrides, and organics require active modification at the first surface reactive monolayer to be able to differentiate them in each process step with respect to any surface normal on the wafer plane. This presentation will start with a review of today's state-of-the-art means for atomic precision processing of surfaces. A simulation science perspective to process integration modeling introduces methods for surface chemistry control that lend themselves to achieving area selective etch. In the end, surface chemistry control is not a cure-all. Finally, a combination of plasma diagnostics and simulation will be needed to assist plasma process controls for scaling at 3 nm and beyond.