NAND TYPE FLASH MEMORY DEVICE AND METHOD OF MANUFACTURING THE SAME

摘要

A NAND-type flash memory device is provided to prevent the edge of an active region in which a thinning phenomenon of a tunnel oxide layer can occur from being used in driving a cell transistor by avoiding using a part of a tunnel oxide layer adjacent to the edge of the active region. An active region(100a) is defined to have an upper surface with a first width along a first direction of a semiconductor substrate(100). A tunnel oxide layer is extended along the first direction over the active region, having the first width. A first floating gate conductive layer(110) is extended along the first direction on the tunnel oxide layer over the active region, having a second width smaller than the first width. A second floating gate conductive layer(130) is extended along the first direction on the first floating gate conductive layer, electrically coming in contact with the fist floating gate conductive layer and having a third width greater than the second width. An intergate dielectric(140) is formed on the second floating gate conductive layer. A control gate conductive layer(150) is formed on the intergate dielectric. The second floating gate conductive layer has a section of a cup type in the first direction, and a concave part is formed in the upper surface of the second floating gate conductive layer.