METHOD FOR FABRICATING FLASH MEMORY DEVICE

摘要

PURPOSE: A method for fabricating a flash memory device is provided to simplify a process and to prevent the degradation of device characteristics, by preventing a dielectric film in a cell region from being damaged during a BOE(Buffered Oxide Etchant) cleaning. CONSTITUTION: A tunnel oxide(102) and a gate conductive film(103) and an ONON dielectric film(104) stacked with a nitride film(104d)/oxide(104c)/nitride film(104b)/oxide(104a) are formed on a semiconductor substrate(101). A photo resist pattern(106) is formed on the ONON dielectric film to etch a part of the ONON dielectric film of a specific transistor like a low voltage transistor or a high voltage transistor in a peripheral circuit region. The ONON dielectric film in the cell region is covered completely by the photo resist and a part of the ONON dielectric film in the peripheral circuit region is revealed. Then, the ONON dielectric film in the peripheral circuit region is etched and after stripping the photo resist by O2 plasma, is cleaned in a BOE solution to remove polymer. And a control gate conductive film is deposited, and a stack gate pattern is completed by performing a gate mask and an etching process.