3D memory device and method of forming 3D memory device

摘要

A method of forming a 3D memory device includes forming an alternating dielectric stack in a contact area on a substrate, forming a plurality of contact holes having various depths vertically extending in the alternating dielectric stack, and a sacrificial-filling layer filling the contact hole. Forming a plurality of dummy channel holes penetrating the alternating dielectric stack in the contact region, filling the dummy channel holes with a dielectric material to form a support, and sacrificing the alternating dielectric stack and the sacrificial-filling layer Replacing the layer with a conductive layer to form a plurality of gate lines and contacts.