Method of fabricating flash memory device

Abstract

The present invention provides a method of fabricating a flash memory device, in which floating gates in neighbor cells are separated from each other without using photolithography, which enhances electrical characteristics of the device, and which facilitates a cell size reduction. The present invention includes forming a mask defining a trench forming area on a semiconductor substrate, forming a trench in the semiconductor layer by removing a portion of the semiconductor layer using the mask, forming a device isolation layer filling up the trench to maintain an effective isolation layer thickness exceeding a predefined thickness, removing the mask, forming a conductor layer over the substrate including the device isolation layer, planarizing the conductor layer and the device isolation layer to lie in a same plane, and forming an insulating layer over the substrate including the conductor patterns.