A method to solve Reverse Tunneling Disturb issue for SuperFlash® memory

Oxygen gas is conventionally used for photoresist ashing process during the fabrication of Integrated Circuits. However, Reverse tunneling disturb fail of flash memory happened frequently if we only use Oxygen gas during photoresist ashing process after floating gate nitride etch. Through physical failure analysis, we found it is reverse word line tip that induce RTD fail. By analysis and comparison, an additional forming gas (N
₂
H
₂
) that can enhance polymer removal during Photo resist ashing process was introduced to solve RTD fail for flash products.