| 摘要 |
PURPOSE:To enhance the integrating density of a memory cell by providing a control gate for implanting charge in a floating gate by utilizing tunnel phenomenon and a programming gate for discharging charged stored in a gate. CONSTITUTION:A control gate 11 made of an N-type diffused region, floating gate 12, source 14, drain 15 and selecting gate 16 made of polycrystalline silicon are formed on a P-type semiconductor substrate. A programming gate 19 is disposed through an insulating film on the gate 12. When electrons are emitted from the gate 12, the gate 11 is set to a low potential, and a gate 19 is raised to a high potential. When electrons are implanted to the gate 12, the gate 11 is set to a high potential; the source 14, drain 15 are dropped to a low potential, and the potential of the gate 16 is raised. |
