N-Channel Erasable Programmable Non-Volatile Memory

摘要

In an embodiment of the invention, a method of fabricating a floating-gate NMOSFET (n-type metal-oxide semiconductor field-effect transistor) is disclosed. A silicide blocking layer (e.g. oxide, nitride) is used not only to block areas from being silicided but to also form an insulator on top of a poly-silicon gate. The insulator along with a top electrode (control gate) forms a capacitor on top of the poly-silicon gate. The poly-silicon gate also serves as the bottom electrode of the capacitor. The capacitor can then be used to capacitively couple charge to the poly-silicon gate. Because the poly-silicon gate is surrounded by insulating material, the charge coupled to the poly-silicon gate may be stored for a long period of time after a programming operation.