Semiconductor device and method for manufacturing the same

A method for manufacturing a semiconductor device including a fin-shaped semiconductor portion having a source region formed on one side thereof and a drain region formed on other side thereof, and a gate electrode formed between said source region and said drain region to surround said fin-shaped semiconductor portion with a gate insulating film interposed therebetween, the method for manufacturing a semiconductor device comprising the steps of:

• forming an insulating film on a semiconductor layer and further forming a film of amorphous silicon;
• patterning said amorphous silicon in a predetermined shape and performing a short-time thermal treatment on said amorphous silicon to crystallize said amorphous silicon;
• forming a sidewall on a side face of said amorphous silicon crystallized;
• sequentially etching said insulating film and said semiconductor layer, using as a mask said sidewall from which said amorphous silicon is removed, to form said fin-shaped semiconductor portion;
• forming a first dummy pattern upon forming said fin-shaped semiconductor portion;
• and
• forming a second dummy pattern upon forming said gate electrode,
• wherein said first dummy pattern is positioned under said second dummy pattern,
• said first dummy pattern is separated from said fin-shaped semiconductor portion,
• said second dummy pattern is separated from said gate electrode, and
• said second dummy pattern does not overlap said first dummy pattern.