NON-VOLATILE MEMORY ELEMENT AND ARRAY

摘要

A metal insulated semiconductor (MIS) field effect transistor is operated in a gate-to-source mode. The voltage threshold of conduction of the transistor is variable and is switched between two different stable threshold conditions in response to application of corresponding, different predetermined values of polarizing voltages applied between the gate and source terminals. Determination of the threshold condition to which the transistor is switched is effected by applying a read voltage to the gate of the transistor intermediate the voltage threshold levels and sensing the current flow between the source and drain. Since the sense voltage is less than the polarizing voltage for either condition of switching, the preset threshold condition is maintained. The transistor therefore exhibits a non-volatile memory capability. A plurality of the transistors are employed in a memory array and may be readily fabricated in integrated circuit form.