Semiconductor devices

A semiconductor device comprising:

• a first semiconductor layer having a first channel region;
• a first source/drain region in the first semiconductor layer on first and second sides of the first channel region;
• a gate structure including a first gate insulating film, a shared gate electrode, and a second gate insulating film sequentially arranged on the first channel region;
• a second semiconductor layer on the second gate insulating film and electrically separated from the first semiconductor layer to provide a second channel region;
• and
• a second source/drain region in the second semiconductor layer on first and second sides of the second channel region.

A semiconductor device comprising:

• a substrate having an active fin that extends in a first direction and that provides a first channel region;
• a gate structure having a first gate insulating film and a shared gate electrode that is perpendicular with the active fin to extend in a second direction and is sequentially disposed on a portion of the active fin;
• a first source/drain region in the active fin on first and second sides of the gate structure;
• a second gate insulating film having a region that overlaps the gate structure and is on the shared gate electrode;
• a cover semiconductor layer on the second gate insulating film and that provides a second channel region;
• and
• a second source/drain region in the cover semiconductor layer on first and second sides of the second channel region.