METHOD OF SUPPRESSING EPITAXIAL GROWTH IN SUPPORT OPENINGS AND THREE-DIMENSIONAL MEMORY DEVICE CONTAINING NON-EPITAXIAL SUPPORT PILLARS IN THE SUPPORT OPENINGS

摘要

Memory openings and support openings are formed through an alternating stack of insulating layers and spacer material layers over a semiconductor substrate. Deposition of a semiconductor material in the support openings during formation of epitaxial channel portions in the memory openings is prevented by Portions of the semiconductor substrate that underlie the support openings are converted into impurity-doped semiconductor material portions. During selective growth of epitaxial channel portions from the semiconductor substrate within the memory openings, growth of a semiconductor material in the support openings is suppressed due to the impurity species in the impurity-doped semiconductor material portions. Memory stack structures and support pillar structures are subsequently formed over the epitaxial channel portions and in the support openings, respectively. The support pillar structures are formed with an outermost dielectric layer to prevent a leakage path to electrically conductive layers to be subsequently formed.