| 摘要 |
<p>PURPOSE:To use a memory cell as a volatile memory or as a nonvolatile memory by integrating the memory cell composed of the following: a first semiconductor region; a charge storage mechanism; a first gate; a second region; a second gate; an on-demand potential-setting means. CONSTITUTION:An N<+> type source region 2 and a drain region 3 which have been formed on the surface of a P-type silicon substrate 1 at mutual intervals and which act as a second region are formed in a single cell. A floating gate 5 is formed, via a gate oxide film 4, on a first semiconductor region 51 as a surface part of the substrate 1 between the source region 2 and the drain region 3. A second control gate 7 is formed, via a second control gate insulating film 6, on the floating gate 5; a first N<+> type control gate region 9 is formed, via a first control gate insulating film 8, in the surface part of the substrate 1 under the floating gate. This single memory cell is integrated. Thereby, it is possible to write volatile information into a nonvolatile information simply and in a short time.</p> |
