Patent ID: 11081443

Abstract:
A first vertically alternating sequence of first insulating layers and first spacer material layers and a first-tier retro-stepped dielectric material portion are formed over a substrate. The first spacer material layers are formed as, or are subsequently replaced with, first electrically conductive layers. A second vertically alternating sequence of second insulating layers and second spacer material layers and a second-tier retro-stepped dielectric material portion are formed over the first vertically alternating sequence and the first-tier retro-stepped dielectric material portion. The second spacer material layers are formed as, or are subsequently replaced with, second electrically conductive layers. An opening is formed through the second vertically alternating sequence over the first-tier retro-stepped dielectric material portion, and is filled with a dielectric well structure. Contact via structures can be formed through the dielectric well structure and the first-tier retro-stepped dielectric material portion on the first electrically conductive layers.