| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a flash memory having a U-shaped floating gate. SOLUTION: After an element isolation film is formed with the top surface and part of both side surfaces protruding from the surface of a substrate, a tunnel oxide film is formed on the substrate between the element isolation films. After a conductive film is formed on the tunnel oxide film so as to have a thickness with which the gap is not filled between the element isolation films, a polishing sacrifice film is formed on the conductive film. A U-shaped self-aligned floating gate is formed between the element isolation films by removing the polishing sacrifice film and the conductive film on the element isolation film and at the same time, and the polishing sacrifice film pattern is left on the floating gate. The walls on both the sides of the floating gate are exposed by recessing the element isolation film using the polishing sacrifice film pattern as a mask, and, by selectively removing the polishing sacrifice film pattern with respect to the floating gate, the top surface of the floating gate is exposed. COPYRIGHT: (C)2007,JPO&INPIT
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