METHOD FOR MANUFACTURING FLASH MEMORY DEVICE

摘要

PURPOSE: A method for manufacturing a flash memory device is provided to prevent damage to a substrate due to a self-align source etching and to improve a gate characteristic. CONSTITUTION: The method for manufacturing a flash memory device forms a gate(48) in which a tunnel oxide film(41), a floating gate(42), an ONO film(43), a control gate(44), a tungsten silicide layer(45), a nitride film(46) and an anti-reflection film(47) are sequentially stacked on a silicon substrate(40) in which a field oxide film is formed. A source region(50) and a drain region(49) are formed in the silicon substrate by ion implantation process. An oxide film for spacer is deposited on the entire structure including the gate electrode. A spacer(51) is formed at both sides of the gate so that the source region is exposed but the drain region is not exposed by etching process. A metal layer(52) is formed on the entire structure. A BPSG film(53) is formed on the entire structure including the metal layer. A contact hole(54) through which the source and drain junction can be exposed is formed. A contact spacer oxide film(55) is formed at both sides of the contact hole.