A 3D NAND memory has vertical NAND strings across multiple memory layers above a substrate, with each memory cell of a NAND string residing in a different memory layer. Word lines in each memory layer each has a series of socket components aligned to embed respective floating gates of a group memory cells. In this way, the word line to floating gate capacitive coupling is enhanced thereby allowing a 4 to 8 times reduction in cell dimension as well as reducing floating-gate perturbations between neighboring cells. At the same time floating-gate to floating-gate crosstalk is reduced. The memory is fabricated by using odd and even subarrays of vertical shafts on a multi-layer slab to create at different times odd and even socket components that overlap to form continuous word lines with socket components. A self-aligned 4-masks process is employed on the multi-layer slab.