Method of fabricating flash memory device and flash memory device fabricated thereby

Abstract

There are provided a method of fabricating a flash memory device and a flash memory device fabricated thereby. The method of fabricating a flash memory device includes forming an isolation layer defining an active region in a semiconductor substrate, wherein the isolation layer is formed to have a protrusion being higher than a top surface of the active region, and to provide a groove in the active region. A conductive layer pattern is formed in the groove. A buffer layer is formed on the semiconductor substrate having the conductive layer pattern. Then, an oxidation barrier layer pattern having a line shape opening across the active region is formed on the buffer layer. The buffer layer and an upper portion of the conductive layer pattern, which are exposed by the opening, are selectively oxidized to form a mask oxide layer at a cross region of the opening and the active region, and simultaneously to form a buffer oxide layer on the isolation layer adjacent to the mask oxide layer. The oxidation barrier layer pattern is removed. Using the mask oxide layer, the buffer oxide layer and the isolation layer as etch masks, the buffer layer and the conductive layer pattern are etched, so as to form a floating gate on the active region.