METHOD FOR FORMING ASYMMETRICAL MOS TRANSISTOR OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for forming an asymmetrical MOS(metal oxide semiconductor) transistor of a semiconductor device is provided to prevent a refresh period for a cell capacitor from being reduced by forming a drain region of a shallow junction structure. CONSTITUTION: A branch part(18) protrudes from a position between two gate lines(16) in a direction vertical to the length direction of an active region(14) wherein the position is an intermediate position of the length direction of the active region in an isolation process. An ion implantation mask is formed in the intermediate position of the active region to which the branch part is coupled in an ion implantation process performed on the active region, and a high energy ion implantation process is performed.