Image Number 3 for United States Patent #6436776.
A shallow impurity diffusion layer adjacent to a gate electrode is formed by forming a side-wall insulating film of the gate electrode twice, and a MOS transistor of the salicide type having improved short-channel effect is embodied. An impurity diffusion layer portion not adjacent to a gate electrode of a source/drain region is formed first by self-alignment with a first side-wall insulating film. After an impurity diffusion layer adjacent to the gate electrode is formed by self-alignment with the gate electrode, a second side-wall insulating film is formed. Silicide films are formed on the gate electrode and source/drain region by self-alignment with the second side-wall insulating film.