METHOD FOR FABRICATING MOS TRANSISTOR

摘要

PURPOSE: A method for fabricating a MOS transistor is provided which can block the diffusion of a boron ion in case of implanting the boron ion to form a source/drain of the MOS transistor. CONSTITUTION: A method for fabricating a MOS transistor prevents the generation of short channel effect, by preventing an impurity implanted to form a source/drain from being diffused to the bottom substrate region of a gate, by including the steps of: forming a gate on top of a substrate(1) where an isolation region is defined by the formation of a field oxide(3); forming a lightly doped source/drain(4) on the bottom of the side substrate through an impurity ion implantation process; forming a side wall(5) on the side of the gate and then forming a heavily doped source/drain(6) on the bottom of the side substrate of the side wall through impurity ion implantation process; and forming a diffusion-resistant layer(7) on the bottom substrate region of the lightly doped source/drain through impurity ion implantation process.