THREE DIMENSIONAL NAND DEVICE HAVING DUMMY MEMORY HOLES AND METHOD OF MAKING THEREOF

摘要

A monolithic three dimensional NAND string includes a plurality of control gate electrodes (3a, b) extending substantially parallel to a major surface of a substrate (100), a memory opening (150) extending substantially perpendicular to the major surface of the substrate and filled with a memory opening material including a memory film (7, 9, 11), and a dummy opening (160) extending substantially perpendicular to the major surface of the substrate and filled with a dummy channel material which is different from the memory opening material. The dummy channel material has a higher Young's modulus than the memory opening material to offset warpage of the substrate due to the one of compressive and tensile stress imposed by the plurality of control gate electrodes on the substrate.