Patent ID: 10971507

Abstract:
A first alternating stack of first insulating layers and first sacrificial material layers with first stepped surfaces is formed over a substrate. A first retro-stepped dielectric material portion is formed on the first stepped surfaces. A second alternating stack of second insulating layers and second sacrificial material layers with second stepped surfaces is formed over the first alternating stack. A second retro-stepped dielectric material portion is formed on the second stepped surfaces. A first conductive via structure is formed through the second retro-stepped dielectric material portion, a bottommost insulating layer of the second alternating stack, and the first retro-stepped dielectric material portion. The sacrificial material layers are replaced with electrically conductive layers. The first conductive via structure is electrically connected to a first electrically conductive layer that replaces a first sacrificial material layer, and is electrically isolated from each second electrically conductive layer in the second alternating stack.