Three-dimensional memory device including discrete charge storage elements and methods of forming the same

Abstract

An alternating stack of disposable material layers and silicon nitride layers is formed over a substrate. Memory openings are formed through the alternating stack, and memory opening fill structures are formed in the memory openings, wherein each of the memory opening fill structures comprises a charge storage material layer, a tunneling dielectric layer, and a vertical semiconductor channel Laterally-extending cavities are formed by removing the disposable material layers selective to the silicon nitride layers and the memory opening fill structures. Insulating layers comprising silicon oxide are formed by oxidizing surface portions of the silicon nitride layers and portions of the charge storage material layers that are proximal to the laterally-extending cavities. Remaining portions of the charge storage material layers form vertical stacks of discrete charge storage elements. Remaining portions of the silicon nitride layers are replaced with electrically conductive layers.