Patent ID: 11289508

Abstract:
Three-dimensional (3D) memory devices and methods for forming the 3D memory devices are provided. For example, a method for forming a 3D memory device is provided. A dielectric stack including interleaved sacrificial layers and dielectric layers is formed on a substrate. A staircase structure is formed on at least one side of the dielectric stack. Dummy channel holes and dummy source holes extending vertically through the staircase structure are formed. A subset of the dummy channel holes is surrounded by the dummy source holes. A dummy channel structure is formed in each dummy channel hole, and interleaved conductive layers and dielectric layers are formed in the staircase structure by replacing, through the dummy source holes, the sacrificial layers in the staircase structure with the conductive layers. A spacer is formed along a sidewall of each dummy source hole to cover the conductive layers in the staircase structure, and a contact is formed within the spacer in each dummy source hole.