METHOD FOR MANUFACTURING FLASH MEMORY DEVICE

摘要

PURPOSE: A method for manufacturing a flash memory device is to prevent a parasitic bipolar action from being produced by forming a low concentration ion implantation region. CONSTITUTION: A p-type semiconductor substrate(31) is implanted with an n-type impurity to form a triple n-well region(32). The substrate is carried out through an ion implantation process by controlling a concentration of a p-type impurity and ion implantation energy, thereby forming the first ion implantation region(33). The substrate with the first ion implantation region formed is implanted with the p-type impurity to form a p-type well region(34). The substrate is carried out through the ion implantation process by controlling a concentration of a n-type impurity and ion implantation energy, thereby forming the second ion implantation region(35). The substrate with the n-type well formed is implanted with the n-type impurity to form a junction region(36).