METHOD FOR MANUFACTURING FLASH MEMORY DEVICE

摘要

PURPOSE: A method for manufacturing a flash memory device is provided to simplify a manufacturing process, by controlling a substantial channel impurity density, i.e. a pure density of impurity so that one step of exposure processes is reduced while a predetermined critical dimension voltage value is obtained. CONSTITUTION: Impurity ions of a p-type or n-type are implanted to form a channel of a high voltage transistor without using an additional ion implantation mask regarding a high voltage transistor region. The first ion implantation mask for forming an impurity channel of the other type of the impurity ions is formed. An ion implantation of the other type is performed to offset the effect caused by the ion implantation of one kind of the impurity ions and to have a predetermined critical dimension voltage value by using the remaining impurity ions of the other kind of the impurity ions. A gate electrode(37) is formed in the high voltage transistor region. The second ion implantation mask for a source/drain is formed, and impurity ions are implanted.