A NEW ERASING METHOD FOR A SINGLE-VOLTAGE LONG-ENDURANCE FLASH MEMORY

A new method to erase a standard (double-poly, stacked-gate NOR-type) Flash cell is proposed. The method, still using tunneling mechanism to extract electron from the floating gate as the conventional one, is b ased on the concept of keeping the electric field constant during the whole erasing operation. The new method has two main advantages with r espect to the conventional one: 1) it does not depend on the supply vo ltage variation and 2) it allows a better reliability in terms of endu rance-induced stress. Results have shown that the Flash device perform ances are greatly improved in terms of stability and endurance reliabi lity until one million cycles.