NAND flash memory device

摘要

A method of fabricating a nonvolatile memory device includes providing a substrate having active regions defined by a plurality of trenches, forming a first isolation layer on the substrate having the plurality of trenches, forming a sacrificial layer on the first isolation layer to fill the trenches, the sacrificial layer including a first region filling lower portions of the trenches and a second region filling portions other than the lower portions, removing the second region of the sacrificial layer, forming a second isolation layer on the first isolation layer and the first region of the sacrificial layer, forming air gaps in the trenches by removing the first region of the sacrificial layer, and removing a portion of the first isolation layer and a portion of the second isolation layer while maintaining the air gaps.

主权项

1. A NAND flash memory device comprising:
a semiconductor substrate including an active region and a trench extending longitudinally in a first direction and adjacent to the active region; a first string selection line and a second string selection line disposed on the substrate and extending in a second direction substantially perpendicular to the first direction; a plurality of word lines disposed between the first string selection line and the second string selection line and extending in the second direction; a first isolation layer formed in a first portion of the trench, the first isolation layer positioned between the first and the second string selection lines; and an air gap formed in a second portion of the trench and extending in the first direction, the second portion formed in the substrate under the plurality of word lines.