Ultrahigh density vertical NAND memory device and method of making thereof

摘要

A method of making a monolithic three dimensional NAND string. The method includes forming a stack of alternating layers of a first material and a second material over a substrate. The first material includes a conductive or semiconductor control gate material and the second material includes an insulating material. The method also includes etching the stack to form at least one opening in the stack, selectively etching the first material to form first recesses in the first material and forming a blocking dielectric in the first recesses. The method also includes forming a plurality of discrete charge storage segments separated from each other in the first recesses over the blocking dielectric, forming a tunnel dielectric over a side wall of the discrete charge storage segments exposed in the at least one opening and forming a semiconductor channel in the at least one opening.