Detailed observation of small leak current in flash memories with thin tunnel oxides

This paper describes a method for measuring the small current through the oxides on the order of 10/sup -20/ A or less using a floating gate MOSFET and the application results on flash memories with thin tunnel oxides. The method is based on accurate measurement of the threshold voltage of a floating gate MOSFET with no charge in the floating gate. We applied the method to flash memories to investigate the leakage current behaviour through thin tunnel oxides with very small areas (