STRESS-INDUCED LEAKAGE CURRENT OF TUNNEL OXIDE DERIVED FROM FLASH MEMORY READ-DISTURB CHARACTERISTICS

This paper describes the characteristics of the stress-induced leakage current of tunnel oxide derived from Flash memory read-disturb charac teristics, The following three items were newly observed. First, the t hreshold voltage shift (Delta V-th) of the memory cell under the gate bias condition(read disturb condition) consists of two regions, a deca y region and a steady-state region, The decay region is due to both th e initial trapping or detrapping of the carriers in the tunnel oxide a nd the decay of the stress-induced leakage current of the tunnel oxide , The steady-state region is determined by the saturation of the stres s-induced leakage current of the tunnel oxide. Second, the read distur b life time is mainly determined by the steady-state region for the ox ide thickness of 5.7-10.6 nm investigated here, Third, a high-temperat ure (125 degrees C) write/erase operation degrades the steady-state re gion characteristics in comparison with room temperature (30 degrees C ) operation, Therefore, accelerated write/erase tests san be carried o ut at higher operation temperatures.