SELECTIVE ETCHING AND DEPOSITION OF MEMORY LAYERS TO PROVIDE CAPACITOR-TO-ACTIVE SILICON ELECTRICAL COUPLING

A substrate processing system includes a memory that stores a recipe of an electrical coupling process for electrical coupling a capacitor to an active silicon region of a memory structure. A system controller, according to the recipe, implements the at least a portion of the electrical coupling process including: performing deposition and etch cycles to remove a portion of one or more dielectric layers from a substrate, enlarge a trench between adjacent bitline structures of the memory structure, and provide access to a polymer layer or a dielectric layer adjacent to an upper portion of the active silicon region; performing a breakthrough operation including etching at least one of the polymer layer or the dielectric layer in the trench to expose the upper portion of the active silicon region; and performing an over-etch operation to provide access for electrically coupling the capacitor to the active silicon region.