| 摘要 |
PURPOSE: A method for manufacturing a flash memory device is to improve electric characteristics of the device and increase the yield and reliability of the device by preventing an etching remainder. CONSTITUTION: An etching target layer is formed on a silicon substrate with a field oxide layer having a step formed therein. A photoresist pattern is formed on the etching target layer. The etching target layer is etched by an isotropy dry etching process using the photoresist pattern as an etching mask. The isotropy dry etching process is conducted at the temperature of 0 to 100 deg.C under the pressure of 200 to 2000 mTor. The etching remainder remaining on the silicon substrate is removed by a BOE(buffered oxide etchant) solution. Then, the photoresist pattern is removed from the silicon substrate. Finally, a cleaning process is conducted in regard to the entire substrate. The etching target layer can be an ONO(oxide-nitride-oxide) layer having the thickness of 200 to 300 angstroms.
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