METHOD FOR FABRICATING EEPROM DEVICE

摘要

PURPOSE: A method for fabricating an EEPROM(electrically erasable and programmable read-only-memory) device is provided to guarantee a growth of an oxide layer at a uniform rate in growing a gate oxide layer and a tunnel oxide layer regardless of an impurity ion implanting process performed on a substrate by independently performing the first and second ion implantation processes for defining a junction region and by forming the gate oxide layer and the tunnel oxide layer. CONSTITUTION: A screen oxide layer is formed on a semiconductor substrate. The first ion implantation mask is formed on the screen oxide layer. The first ion implantation process is performed on the front surface of the substrate. The first heat treatment is performed on the substrate. The first ion implantation mask and the screen oxide layer are eliminated. A gate oxide layer is formed on the substrate. The second ion implantation mask is formed on the gate oxide layer. The second ion implantation process is performed on the substrate. The second heat treatment is performed on the substrate. The second ion implantation mask is eliminated. A tunnel oxide layer is formed on the substrate including the gate oxide layer.