| 摘要 |
PURPOSE: A method for fabricating a flash memory is provided to form differently the depth of trench corresponding to a cell region and a peripheral region by controlling an etching angle and an etching period. CONSTITUTION: A pad oxide layer and a pad nitride layer are formed on a semiconductor substrate(402). A trench having different depth is formed by etching the pad nitride layer, the pad oxide layer, and the semiconductor substrate(402). A trench insulating layer(412) is deposited on the entire surface of the resultant structure in order to bury the inside of the trench. The protruded trench is formed by performing a planarization process and a strip process for the trench insulating layer. A well region is formed by performing an ion implantation process. A tunnel oxide layer(416), a floating gate, a dielectric layer(420), and a control gate are formed thereon.
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