| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of manufacturing a nonvolatile memory element which doesn't affect a height of a control gate. SOLUTION: The method of manufacturing the nonvolatile memory element comprises the steps of forming a first trench having a first depth on a silicon substrate 100 in peripheral circuit regions, and flattening the first trench by a buried oxide film 130; forming a second trench having a second depth on a silicon substrate in a cell region; implanting a channel ion into the cell region, forming a tunnel oxide film 140 inside the second trench, and depositing a floating gate substance; etching the floating gate substance and forming a floating gate 150'; forming a source / drain junction 160 in the cell region; forming wells in the peripheral circuit regions and cell region and depositing a dielectric film 170; leaving the dielectric film 170 only at a channel portion in the cell region and depositing the gate substance; and etching the gate substance, forming gates in the peripheral circuit regions, and forming a control gate 180' in the cell region. COPYRIGHT: (C)2005,JPO&NCIPI
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