| 摘要 |
<p>PURPOSE: A method for manufacturing a flash memory device is provided to reduce the thickness of a memory gate by securing a profile and a cross section of a selective gate. CONSTITUTION: An ONO(Oxide-Nitride-Oxide) layer is formed on a semiconductor substrate defined with an active region and a device isolation region. A memory gate(140) is formed on the ONO layer by using a first poly silicon. A gate oxide layer is formed on both sides and the upper side of the memory gate. A second poly silicon is formed on the semiconductor substrate including the gate oxide layer. A third poly silicon is dually formed on the second poly silicon. The part of the second and third poly silicon is planarized. A selective gate(220) is formed by selectively etching the part of the second poly silicon.</p> |
