CHARGE STORAGE MODEL FOR VARIABLE THRESHOLD FET MEMORY ELEMENT

A simple two-layer model is presented for charge storage in a MI 2I1S device in which the times for charging and discharging are expressed in closed-form expressions depending on the conduction properties, the thicknesses, and the dielectric constants of the two layers. Data were taken using silicon oxide for I1 and silicon nitride for I2 which are in good agreement with the model. The model is quite general and should be valid for other insulators and other conduction mechanisms. © 1969 The American Institute of Physics.