Patent ID: 6720217
Filing Date: 2004-04-13
Classification: H01L

Abstract:
A method of manufacturing a flash memory device using trench isolation process, comprising the steps of:(a) sequentially depositing a pad oxide film and a pad nitride film on a semiconductor substrate; (b) forming trenches by etching the pad nitride film, the pad oxide film and the substrate using a mask for forming a device isolation film, wherein the trenches have a different depth in a cell region and in a peripheral region formed simultaneously by controlling an etch angle and etch target depending on the width of the trenches formed in the cell region and the peripheral region, and the trench in a peripheral region is formed to be deeper than the trench in a cell region; (c) depositing trench insulating films on the entire surfaces of the semiconductor substrate to bury the trenches with the trench insulating films; (d) performing a planarization process and a strip process for the trench insulating films to form the trench insulating films upper structures of which are protruded; (e) forming a well region through an ion implantation process in the semiconductor substrate; and (f) forming a tunnel oxide film, a floating gate, a dielectric film and a control gate on the predetermined area of the semiconductor substrate.