| 摘要 |
PURPOSE: A method for fabricating a non-volatile memory(NVM) device is provided to reduce the size of the memory device by forming an NVM device of a vertical structure using two trenches, and to decrease the number of masks by forming the NVM device using a trench and a sidewall. CONSTITUTION: The first trench is formed on a substrate(1) of the first conductivity type. The second trench having a width narrower than that of the first trench is formed inside the first trench. An ion implantation process for controlling a threshold voltage is formed on the entire surface including the first and second trenches. The first insulation layer sidewall is formed on the sidewall of the first and second trenches. Impurity ions of the second conductivity type are implanted into the exposed surface of the substrate and the bottom surface of the first and second trenches so that a source/drain region(7) is formed. The second insulation layer is deposited on the substrate. A floating gate(9a) and a gate electrode are formed on the sidewall of the second insulation layer inside the first and second trenches, respectively. The third insulation layer is deposited on the substrate. A control gate(12a) is formed on the sidewall of the third insulation layer at a side surface of the first trench.
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