Semiconductor device and method for fabricating the same

A semiconductor device comprising:

• a substrate comprising a first side and a second side that is opposite to the first side;
• an active pattern that is on the first side and extends in a first direction;
• a field insulating film that is on the first side and covers at least a part of side faces of the active pattern;
• an etch stop layer that is between the substrate and the field insulating film and not between the active pattern and the field insulating film;
• a gate structure that extends in a second direction intersecting the first direction, on the active pattern and the field insulating film;
• a through contact that extends in a third direction intersecting the first direction and the second direction, and penetrates the field insulating film and the etch stop layer;
• a buried pattern connected to the through contact, inside the substrate;
• and
• a backside wiring structure that is on the second side and electrically connected to the buried pattern.

A semiconductor device comprising:

• a substrate comprising a first side and a second side that is opposite to the first side;
• an active pattern that is on the first side and extends in a first direction;
• an epitaxial liner film extending along the first side of the substrate and side faces of the active pattern;
• an etch stop layer that extends, on the epitaxial liner film, along the first side and does not extend along the side faces of the active pattern;
• a field insulating film that is on the etch stop layer and covers at least a part of the side faces of the active pattern;
• a gate structure that extends on the active pattern and the field insulating film in a second direction intersecting the first direction;
• a source/drain region connected to the active pattern on the side faces of the gate structure;
• a frontside wiring structure that is on the first side and electrically connected to the source/drain region or the gate structure;
• a through contact that is electrically connected to the source/drain region, and penetrates the field insulating film and the etch stop layer;
• a buried pattern connected to the through contact, inside the substrate;
• and
• a backside wiring structure that is on the second side and electrically connected to the buried pattern.