Patent ID: 7733700

Claim:
A method for programming a metal oxide semiconductor field effect transistor (MOSFET) in a non-volatile memory cell, said transistor having a source, a drain and a channel region between the source and the drain, said source, drain and channel region being formed in a substrate of opposite conductivity type to the conductivity type of said source and said drain, said method comprising: connecting the drain electrode of said MOSFET to either the supply source of the main voltage, or ground, provided to said non-volatile memory cell; inverting a portion of the channel region extending from the source toward the drain, the inverted portion of the channel region ending at a pinch-off point before reaching the drain; and optimizing the programming efficiency of the MOSFET by reverse biasing the PN junction between the source and substrate to a selected reverse-biased voltage thereby to pull the pinch-off point of the inversion region back toward the source.