| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent characteristics of a nonvolatile storage cell from being deteriorated by allowing a tunnel of the storage cell having an insulating charge trap film as a charge storage region to be erased. SOLUTION: The nonvolatile storage cell comprises a silicon oxide film (2), a polysilicon film (3), a silicon nitride film (4), a silicon oxide film (5) and a gate electrode (6) formed on a channel region (9) between a source region (8) and a drain region (7). The storage cell further comprises interface state density formed by a polysilicon film and a silicon nitride film to the film (2) side of a tunnel discharging side, and a main body of holding charge for storing information carried to the interface state density so that the silicon nitride film can be thinned. Even when a charge discharging operation like an erasing operation of the storage cell used to hold the charge in the silicon nitride film is executed by the tunneling, a state in which the electrons are retained without consuming in the gate insulating film can be prevented. Thus, the erasure by an injection of hot hole is not required.</p> |
