Three-dimensional memory device with mobility-enhanced vertical channels and methods of forming the same

Abstract

A combination of an alternating stack and a memory opening fill structure is provided over a substrate. The alternating stack includes insulating layers and electrically conductive layers. The memory opening fill structure vertically extends through the alternating stack, and includes a memory film, a vertical semiconductor channel, and a core structure comprising a core material. A phase change material is employed for the core material. A volume expansion is induced in the core material by performing an anneal process that induces a microstructural change within the core material. The volume expansion in the core material induces a lateral compressive strain and a vertical tensile strain within the vertical semiconductor channel. The vertical tensile strain enhances charge mobility in the vertical semiconductor channel, and increases the on-current of the vertical semiconductor channel.