Patent attributes
A memory device and a method of fabricating a memory device that includes forming a protrusion over a substrate, an etch stop layer over the protrusion, and a stack of alternating material layers over the etch stop layer. The method further includes etching the stack to the etch stop layer to form a memory opening having a first width dimension proximate to the etch stop layer, etching the etch stop layer to provide a void area between the protrusion and a bottom of the memory opening, where the void area has a second width dimension that is larger than the first width dimension, forming a memory film over a sidewall of the memory opening and within the void area over the top surface of the protrusion, etching the memory film to expose the protrusion, and forming a semiconductor channel in the memory opening that is electrically coupled to the protrusion.