Floating gate memory with improved dielectric

摘要

The dielectric between the floating gate and the control gate, in an EEPROM or other floating gate memory is made by forming an oxide/nitride stack over the (first polysilicon) control gate. This dielectric not only provides a very high specific capacitance, which is desired to provide tight coupling of the control to the floating gate, but also provides excellent dielectric integrity. Moreover, the thickness of this dielectric layer does not exhibit any uncontrolled increase during exposure to second gate oxidation. Thus, the polysilicon-to-polysilicon dielectric is not only of high specific capacitance and high integrity, it is also very uniform.