Three-dimensional memory devices and methods for forming the same

Abstract

A three-dimensional (3D) memory device includes a stack structure having interleaved conductive layers and dielectric layers, and a channel structure extending through the stack structure along a first direction. The channel structure is in contact with a source of the 3D memory device at a bottom portion of the channel structure. The channel structure includes a semiconductor channel, and a memory film over the semiconductor channel. The memory film includes a first angled structure, and a first diameter of the memory film at the bottom portion below the first angled structure is smaller than a second diameter of the memory film at an upper portion above the first angled structure.