Crystalline layer stack for forming conductive layers in a three-dimensional memory structure

Abstract

A stack of alternating layers comprising first epitaxial semiconductor layers and second epitaxial semiconductor layers is formed over a single crystalline substrate. The first and second epitaxial semiconductor layers are in epitaxial alignment with a crystal structure of the single crystalline substrate. The first epitaxial semiconductor layers include a first single crystalline semiconductor material, and the second epitaxial semiconductor layers include a second single crystalline semiconductor material that is different from the first single crystalline semiconductor material. A backside contact opening is formed through the stack, and backside cavities are formed by removing the first epitaxial semiconductor layers selective to the second epitaxial semiconductor layers. A stack of alternating layers including insulating layers and electrically conductive layers is formed. Each insulating layer contains a dielectric material portion deposited within a respective backside cavity. Each electrically conductive layer contains a material from a portion of a respective second epitaxial semiconductor layer.