| 摘要 |
PURPOSE:To improve the integration of MISIC of an ultraviolet ray erase type EPROM or the like and to reduce variability of the characteristics by providing a control gate extending on a field insulating film through a floating gate buried in a dent between the field insulating films so as to level the dent. CONSTITUTION:A P type region 12 for forming a P type channel cut region and a P type channel region and a field oxide film 13 are formed on a P<-> type Si substrate 11. Next, the patterning of the field oxide film 13 is performed using a resist mask and then a first gate oxide film is formed on the exposed surface of the substrate. In this process, a transistor arranged region 15 of a dent form having a first gate oxide film 14 is formed. A polycrystalline Si layer which fills up the transistor arranged region 15 completely and has an almost flat surface is formed. Next, the polycrystalline Si layer is made to be a first N<+> type polycrystalline Si layer 16. Then the first polycrystalline Si layer 16 is etched from the upper gradually till the upper surface of the field oxide film 13 is exposed. Next, a second gate oxide film 17 is formed on the first N<+> type polycrystalline Si layer 16. |
