THREE-DIMENSIONAL MEMORY STRUCTURE HAVING SELF-ALIGNED DRAIN REGIONS AND METHODS OF MAKING THEREOF

摘要

A memory stack structure can be formed through a stack of an alternating plurality of first material layers and second material layers and through an overlying temporary material layer having a different composition than the first and second material layers. The memory stack structure can include a memory film and a semiconductor channel layer. The overlying temporary material layer is removed selective to the stack to form a lateral recess. Portions of the memory film are removed around the lateral recess, and dopants are laterally introduced into an upper portion of the semiconductor channel to form a self-aligned drain region.

主权项

1. A method of manufacturing a three-dimensional memory structure, comprising:
forming a stack of alternating layers comprising first material layers and second material layers over a substrate; forming a temporary material layer over the stack; wherein the temporary material layer has a different composition than the first material layers and second material layers; forming a memory opening through the temporary material layer and the stack; forming a memory film and a semiconductor channel in the memory opening; forming a first backside recess by removing the temporary material layer and a portion of the memory film that adjoins the temporary material layer, wherein a portion of a sidewall of the semiconductor channel is physically exposed to the first backside recess; and introducing electrical dopants through the physically exposed portion of the sidewall of the semiconductor channel and into a portion of the semiconductor channel, which is converted into a drain region.