Three-dimensional memory devices with drain-select-gate cut structures and methods for forming the same

Abstract

A method for forming a three-dimensional (3D) memory device includes forming a dielectric stack including a plurality of first/second dielectric layer pairs over a substrate, forming a plurality of channel structures extending in a lateral direction in a core region of the dielectric stack, forming a staircase structure including a plurality of stairs extending along the lateral direction in a staircase region of the dielectric stack, forming a first drain-select-gate (DSG) cut opening extending in the lateral direction in the core region and a second DSG cut opening in the staircase region, and forming a first DSG cut structure in the first DSG cut opening and a second DSG cut structure in the second DSG cut opening.