METHOD FOR FABRICATING SEMICONDUCTOR DEVICE TO AVOID HUMP PHENOMENON CAUSED BY UNIFORM ION DENSITY DISTRIBUTION

摘要

PURPOSE: A method for fabricating a semiconductor device is provided to avoid a hump phenomenon caused by a uniform ion density distribution by forming a well region and a region having threshold voltage control ions after a high temperature heat treatment process like an oxide process for forming a tunnel oxide layer. CONSTITUTION: After a tunnel oxide layer(14) and a conductive layer are sequentially formed on a semiconductor substrate(10), a patterning process is performed to form a floating gate electrode. An ion implantation process is performed to form a well region(24) in the semiconductor substrate by using the floating gate electrode as an ion implantation mask. A spacer is formed on the sidewall of the floating gate electrode. A region(26) having the threshold voltage control ions is formed on the surface of the well region by performing an ion implantation process using the spacer and the floating gate electrode as an ion implantation mask.