Patent ID: 11387166

Abstract:
Devices are formed on a substrate. A first-tier alternating stack of first insulating layers and first spacer material layers having first stepped surfaces and a first retro-stepped dielectric material portion are formed over the substrate. A sacrificial contact via structure is formed through the first retro-stepped dielectric material portion. A second-tier alternating stack of second insulating layers and second spacer material layers is formed with second stepped surfaces. A second retro-stepped dielectric material portion including a doped silicate glass liner and a silicate glass material portion is formed over the second stepped surfaces. Memory stack structures are formed through the second-tier alternating stack and the first-tier alternating stack. A contact via cavity is formed down to the sacrificial contact via structure. The doped silicate glass liner is recessed and the sacrificial contact via structure is removed, to form a contact via structure in the contact via cavity.