Semiconductor device and manufacturing method thereof

A semiconductor device including an n-channel transistor and a p-channel transistor, each of said transistors comprising:

• a source region;
• a drain region;
• a channel formation region between said source and drain regions;
• a gate insulating film and a gate electrode formed over said channel formation region,
• at least first and second impurity regions formed in said channel formation region wherein said first and second impurity regions extend in a carrier flow direction of said channel formation region and are arranged in a direction perpendicular to said carrier flow direction,
• wherein a gap between said first and second impurity regions in said n-channel transistor is narrower than a gap between said first and second impurity regions in said p-channel transistor.