| 摘要 |
PURPOSE:To raise the performance of the memory element by composing a memory part of the layers of SiO2, Si3N4, multicrystal Si and SiO2 and a gate electrode provided on an Si substrate in the memory element having a memory part and an auxiliary memory part in respect to the memory of SNOS and MNOS types. CONSTITUTION:On the surface region of the Si sibstrate 11, a source region 12 and a drain region 12' are formed diffusively and on the whole surface inclusive of these regions are laminated fitly the SiO2 layer 13 and the Si3N4 layer 14. On the occasion, the thickness of the layers 13 and 14 is thinned at the central part TR5 between the regions 12 and 12' and the part is employed as the memory part, while the parts TR4 and TR6 of the layers 13 and 14 surrounding the thinned part are thickened so as to be employed as the auxiliary memory part. Next, in the central concavity of the memory part, the multicrystal Si layer 17 is provided, the surface of the memory part and the auxiliary memory part is covered with the thick SiO2 layer 18, while the central region thereof alone is thinned and there the Al gate electrode 15 is attached. After that, an opening is made in the layer 13 and a source electrode 16 and a drain electrode 16' contacting respectively with the regions 12 and 12' are formed therein. |
