METHOD FOR FABRICATING SEMICONDUCTOR TRANSISTOR

摘要

PURPOSE: A method for fabricating a semiconductor transistor is provided to improve an operation characteristic of the semiconductor transistor by decreasing a resistance value of an impurity region while a high impurity density in the impurity region is maintained. CONSTITUTION: A gate electrode(34) is formed on a semiconductor substrate(10). The first spacer is formed on a side part of the gate electrode. Impurity ions are implanted into the semiconductor substrate at the first ion implantation angle with respect to the vertical surface of the semiconductor substrate by using the gate electrode including the first spacer as a mask so that a low density source/drain region(36a,36b) is formed at a side part of the gate electrode. The second spacer is formed at a side part of the first spacer. Impurity ions are implanted into the low density source/drain region at the second ion implantation angle with respect to the vertical surface of the semiconductor substrate by using the gate electrode including the second spacer as a mask. Impurity ions are implanted into the low density source/drain region in a direction perpendicular to the semiconductor substrate so that a high density source/drain region(44a,44b) is formed in the low density source/drain region.