Described is an ultra-dense ferroelectric memory. The memory is fabricated using a patterning method by that applies atomic layer deposition with selective dry and/or wet etch to increase memory density at a given via opening. A ferroelectric capacitor in one example comprises: a first structure (e.g., first electrode) comprising metal; a second structure (e.g., a second electrode) comprising metal; and a third structure comprising ferroelectric material, wherein the third structure is between and adjacent to the first and second structures, wherein a portion of the third structure is interdigitated with the first and second structures to increase surface area of the third structure. The increased surface area allows for higher memory density.