| 摘要 |
A Flash EPROM cell having buried source-side injection is disclosed which allows for low voltage programming from the source side. A cell having the inventive structure can be programmed at 4.0 V or less. The inventive cell comprises a source area which is at a lower plane than the drain region, and a program charge is transferred to the floating gate through the source-side injector. Instead of using a self-aligned high-energy n-type dopant implant at the source side to form the source side injector as used with previous cells, which can be difficult to control, etching the substrate before doping it with impurities allows for the controllable formation of a sharp point of doped silicon, and allows for improved programming at a lower voltage.
|
